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A Ca2+-activated monovalent cation-selective TRPM4 channel is abundantly expressed in the heart. Recently, a single gain-of-function mutation identified in the distal N-terminus of the human TRPM4 channel (Glu5 to Lys5; E7K) was found to be arrhythmogenic because of enhanced cell membrane expression. In this study, we conducted detailed analyses of this mutant channel from more functional aspects, in comparison with its wild type (WT). In an expression system, intracellular application of a short soluble PIP2 (diC8PIP2) restored the single-channel activities of both WT and E7K, which had quickly faded after membrane excision. The potency (Kd) of diC8PIP2 for this recovery was stronger in E7K than its WT (1.44 vs. 2.40 μM). FRET-based PIP2 measurements combined with the Danio rerio voltage-sensing phosphatase (DrVSP) and patch clamping revealed that lowering the endogenous PIP2 level by DrVSP activation reduced the TRPM4 channel activity. This effect was less prominent in E7K than its WT (apparent Kd values estimated from DrVSP-mediated PIP2 depletion: 0.97 and 1.06 μM, respectively), being associated with the differential PIP2-mediated modulation of voltage dependence. Moreover, intracellular perfusion of short N-terminal polypeptides containing either the ‘WT’ or ‘E7K’ sequences respectively attenuated the TRPM4 channel activation at whole-cell and single-channel levels, but in both configurations, the E7K polypeptide exerted greater inhibitory effects. These results collectively suggest that N-terminal interaction with endogenous PIP2 is essential for the TRPM4 channel to function, the extent of which may be abnormally strengthened by the E7K mutation through modulating voltage-dependent activation. The altered PIP2 interaction may account for the arrhythmogenic potential of this mutation.
Yaopeng Hu; Qin Li; Lin-Hai Kurahara; Narumi Shioi; Keizo Hiraishi; Takayuki Fujita; Xin Zhu; Ryuji Inoue. An Arrhythmic Mutation E7K Facilitates TRPM4 Channel Activation via Enhanced PIP2 Interaction. Cells 2021, 10, 983 .
AMA StyleYaopeng Hu, Qin Li, Lin-Hai Kurahara, Narumi Shioi, Keizo Hiraishi, Takayuki Fujita, Xin Zhu, Ryuji Inoue. An Arrhythmic Mutation E7K Facilitates TRPM4 Channel Activation via Enhanced PIP2 Interaction. Cells. 2021; 10 (5):983.
Chicago/Turabian StyleYaopeng Hu; Qin Li; Lin-Hai Kurahara; Narumi Shioi; Keizo Hiraishi; Takayuki Fujita; Xin Zhu; Ryuji Inoue. 2021. "An Arrhythmic Mutation E7K Facilitates TRPM4 Channel Activation via Enhanced PIP2 Interaction." Cells 10, no. 5: 983.
Bowman–Birk inhibitors (BBIs) are plant-derived serine proteinase inhibitors. Endogenously, they function as defense molecules against pathogens and insects, but they also have been explored for applications in cancer treatment and inflammatory disorders. Here, we isolated 15 novel BBIs from the bulb of Hyacinthus orientalis (termed HOSPIs). These isoinhibitors consisted of two or three chains, respectively, that are linked by disulfides bonds based on proposed cleavage sites in the canonical BBI reactive site loop. They strongly inhibited trypsin (Ki = 0.22–167 nM) and α-chymotrypsin (Ki = 19–1200 nM). Notably, HOSPI-B4 contains a six-residue reactive loop, which appears to be the smallest such motif discovered in BBIs to date. HOSPI-A6 and -A7 contain an unusual reactive site, i.e. Leu–Met at the P1–P1′ position and have strong inhibitory activity against trypsin, α-chymotrypsin, and elastase. Analysis of the cDNA encoding HOSPIs revealed that the precursors have HOSPI-like domains repeated at least twice with a defined linker sequence connecting individual domains. Lastly, mutational analysis of HOSPIs suggested that the linker sequence does not affect the inhibitory activity, and a Thr residue at the P2 site and a Pro at the P3′ site are crucial for elastase inhibition. Using mammalian proteases as representative model system, we gain novel insight into the sequence diversity and proteolytic activity of plant BBI. These results may aid the rational design of BBI peptides with potent and distinct inhibitory activity against human, pathogen, or insect serine proteinases.
Narumi Aoki-Shioi; Shigeyuki Terada; Roland Hellinger; Yoshitaka Furuta; Christian W. Gruber. Isolation and functional diversity of Bowman–Birk type serine proteinase inhibitors from Hyacinthus orientalis. Biochemical Journal 2021, 478, 1287 -1301.
AMA StyleNarumi Aoki-Shioi, Shigeyuki Terada, Roland Hellinger, Yoshitaka Furuta, Christian W. Gruber. Isolation and functional diversity of Bowman–Birk type serine proteinase inhibitors from Hyacinthus orientalis. Biochemical Journal. 2021; 478 (6):1287-1301.
Chicago/Turabian StyleNarumi Aoki-Shioi; Shigeyuki Terada; Roland Hellinger; Yoshitaka Furuta; Christian W. Gruber. 2021. "Isolation and functional diversity of Bowman–Birk type serine proteinase inhibitors from Hyacinthus orientalis." Biochemical Journal 478, no. 6: 1287-1301.
Venomous snakebite is a major human health issue in many countries and has been categorized as a neglected tropical disease by the World Health Organization. Venomous snakes have evolved to produce venom, which is a complex mixture of toxic proteins and peptides, both enzymatic and nonenzymatic in nature. In this current era of high-throughput technologies, venomics projects, which include genome, transcriptome, and proteome analyses of various venomous species, have been conducted to characterize divergent venom phenotypes and the evolution of venom-related genes. Additionally, venomics can also inform about mechanisms of toxin production, storage, and delivery. Venomics can guide antivenom and therapeutic strategies against envenomations and identify new toxin-derived drugs/tools. One potentially promising drug development direction is the use of endogenous inhibitors present in snake venom glands and serum that could be useful for snakebite therapeutics. These inhibitors suppress the activity of venom proteases, enzymatic proteins responsible for the irreversible damage from snakebite. This book chapter will focus on insights from venomous snake adaptations, such as the evolution of venom proteases to generate diverse activities and snake natural resistance to inhibit activity, and how this information can inform and have applications in the treatment of venomous snakebite.
Narumi Aoki-Shioi; Cassandra M. Modahl. Snakebite Therapeutics Based on Endogenous Inhibitors from Vipers. Medical Toxicology 2021, 1 .
AMA StyleNarumi Aoki-Shioi, Cassandra M. Modahl. Snakebite Therapeutics Based on Endogenous Inhibitors from Vipers. Medical Toxicology. 2021; ():1.
Chicago/Turabian StyleNarumi Aoki-Shioi; Cassandra M. Modahl. 2021. "Snakebite Therapeutics Based on Endogenous Inhibitors from Vipers." Medical Toxicology , no. : 1.
Snake venoms are complex mixtures of enzymes and nonenzymatic proteins that have evolved to immobilize and kill prey animals or deter predators. Among them, three-finger toxins (3FTxs) belong to the largest superfamily of nonenzymatic proteins. They share a common structure of three β-stranded loops extending like fingers from a central core containing all four conserved disulfide bonds. Most 3FTxs are monomers and through subtle changes in their amino acid sequences, they interact with different receptors, ion channels and enzymes to exhibit a wide variety of biological effects. The 3FTxs have further expanded their pharmacological space through covalent or noncovalent dimerization. Synergistic-type toxins (SynTxs) isolated from the deadly mamba venoms, although nontoxic, have been known to enhance the toxicity of other venom proteins. However, the details of three-dimensional structure and molecular mechanism of activity of this unusual class of 3FTxs are unclear. We determined the first three-dimensional structure of a SynTx isolated from Dendroaspis jamesoni jamesoni (Jameson's mamba) venom. The SynTx forms a unique homodimer that is held together by an interchain disulfide bond. The dimeric interface is elaborate and encompasses loops II and III. In addition to the inter-subunit disulfide bond, the hydrogen bonds and hydrophobic interactions between the monomers contribute to the dimer formation. Besides, two sulfate ions that mediate interactions between the monomers. This unique quaternary structure is evolved through noncovalent homodimers such as κ-bungarotoxins. This novel dimerization further enhances the diversity in structure and function of 3FTxs.
Narumi Aoki-Shioi; Chacko Jobichen; J. Sivaraman; R. Manjunatha Kini. Unusual quaternary structure of a homodimeric synergistic-type toxin from mamba snake venom defines its molecular evolution. Biochemical Journal 2020, 477, 3951 -3962.
AMA StyleNarumi Aoki-Shioi, Chacko Jobichen, J. Sivaraman, R. Manjunatha Kini. Unusual quaternary structure of a homodimeric synergistic-type toxin from mamba snake venom defines its molecular evolution. Biochemical Journal. 2020; 477 (20):3951-3962.
Chicago/Turabian StyleNarumi Aoki-Shioi; Chacko Jobichen; J. Sivaraman; R. Manjunatha Kini. 2020. "Unusual quaternary structure of a homodimeric synergistic-type toxin from mamba snake venom defines its molecular evolution." Biochemical Journal 477, no. 20: 3951-3962.
The CAP protein superfamily (Cysteine-rich secretory proteins (CRISPs), Antigen 5 (Ag5), and Pathogenesis-related 1 (PR-1) proteins) is widely distributed, but for toxinologists, snake venom CRISPs are the most familiar members. Although CRISPs are found in the majority of venoms, very few of these proteins have been functionally characterized, but those that have been exhibit diverse activities. Snake venom CRISPs (svCRISPs) inhibit ion channels and the growth of new blood vessels (angiogenesis). They also increase vascular permeability and promote inflammatory responses (leukocyte and neutrophil infiltration). Interestingly, CRISPs in lamprey buccal gland secretions also manifest some of these activities, suggesting an evolutionarily conserved function. As we strive to better understand the functions that CRISPs serve in venoms, it is worth considering the broad range of CRISP physiological activities throughout the animal kingdom. In this review, we summarize those activities, known crystal structures and sequence alignments, and we discuss predicted functional sites. CRISPs may not be lethal or major components of venoms, but given their almost ubiquitous occurrence in venoms and the accelerated evolution of svCRISP genes, these venom proteins are likely to have functions worth investigating.
Takashi Tadokoro; Cassandra M. Modahl; Katsumi Maenaka; Narumi Aoki-Shioi. Cysteine-Rich Secretory Proteins (CRISPs) from Venomous Snakes: An Overview of the Functional Diversity in a Large and Underappreciated Superfamily. Toxins 2020, 12, 175 .
AMA StyleTakashi Tadokoro, Cassandra M. Modahl, Katsumi Maenaka, Narumi Aoki-Shioi. Cysteine-Rich Secretory Proteins (CRISPs) from Venomous Snakes: An Overview of the Functional Diversity in a Large and Underappreciated Superfamily. Toxins. 2020; 12 (3):175.
Chicago/Turabian StyleTakashi Tadokoro; Cassandra M. Modahl; Katsumi Maenaka; Narumi Aoki-Shioi. 2020. "Cysteine-Rich Secretory Proteins (CRISPs) from Venomous Snakes: An Overview of the Functional Diversity in a Large and Underappreciated Superfamily." Toxins 12, no. 3: 175.
Background Acetaldehyde, produced upon exposure to alcohol, cigarette smoke, polluted air and sugar, is a highly reactive compound that is carcinogenic to humans and causes a variety of DNA lesions in living human cells. Previously, we reported that acetaldehyde reacts with adjacent deoxyguanosine residues on oligonucleotides, but not with single deoxyguanosine residues or other deoxyadenosine, deoxycytosine, or thymidine residues, and revealed that it forms reversible intrastrand crosslinks with the dGpdG sequence (GG dimer). Results Here, we show that restriction enzymes that recognize a GG sequence digested acetaldehyde-treated plasmid DNA with low but significant efficiencies, whereas restriction enzymes that recognize other sequences were able to digest such DNA. This suggested that acetaldehyde produced GG dimers in plasmid DNA. Additionally, acetaldehyde-treated oligonucleotides were efficient in preventing digestion by the exonuclease function of T4 DNA polymerase compared to non-treated oligonucleotides, suggesting structural distortions of DNA caused by acetaldehyde-treatment. Neither in vitro DNA synthesis reactions of phi29 DNA polymerase nor in vitro RNA synthesis reactions of T7 RNA polymerase were observed when acetaldehyde-treated plasmid DNA was used, compared to when non-treated plasmid DNA was used, suggesting that acetaldehyde-induced DNA lesions inhibited replication and transcription in DNA metabolism. Conclusions Acetaldehyde-induced DNA lesions could affect the relative resistance to endo- and exo-nucleolytic activity and also inhibit in vitro replication and in vitro transcription. Thus, investigating the effects of acetaldehyde-induced DNA lesions may enable a better understanding of the toxicity and carcinogenicity of acetaldehyde.
Haruka Tsuruta; Yuina Sonohara; Kosuke Tohashi; Narumi Aoki Shioi; Shigenori Iwai; Isao Kuraoka. Effects of acetaldehyde-induced DNA lesions on DNA metabolism. Genes and Environment 2020, 42, 1 -7.
AMA StyleHaruka Tsuruta, Yuina Sonohara, Kosuke Tohashi, Narumi Aoki Shioi, Shigenori Iwai, Isao Kuraoka. Effects of acetaldehyde-induced DNA lesions on DNA metabolism. Genes and Environment. 2020; 42 (1):1-7.
Chicago/Turabian StyleHaruka Tsuruta; Yuina Sonohara; Kosuke Tohashi; Narumi Aoki Shioi; Shigenori Iwai; Isao Kuraoka. 2020. "Effects of acetaldehyde-induced DNA lesions on DNA metabolism." Genes and Environment 42, no. 1: 1-7.
Snakebites are a hazard in the tropical world. Although antivenom therapy is effective, it is beset with inherent drawbacks. A better understanding of the major components of snake venoms and their neutralisation will help in improving snakebite treatment. Snake venom metalloproteinases (SVMPs) are responsible for severe haemorrhage, the inhibition of coagulation and platelet aggregation, observed in the victims of snakebite envenoming. Inhibitors from various sources including medicinal plants, animal venoms, and sera are sought to block the pharmacological functions of SVMPs. In this review, we describe the interaction of natural inhibitors with SVMPs. To understand their inhibitory mechanisms, we focussed on the complex structures of these inhibitors and SVMPs. There are three distinct classes of inhibitors; namely, chelators, competitive inhibitors, and non-competitive inhibitors. A small number of inhibitors show their anti-hemorrhagic activity in invivo animal models in treatment mode, but most studies evaluate either invitro neutralisation of enzymatic activity or invivo effects in pre-incubation protocols. We propose the distinct strategies and limitations to design either broad-spectrum or highly selective SVMP inhibitors. The goal of designing broad-spectrum inhibitors against SVMPs capable of effective treatment of snakebites without toxicity has been elusive, probably because of the narrow molecular footprint of inhibitors against a large number of SVMPs with distinct molecular surfaces. Our ability to design highly selective inhibitors is limited by the lack of information of interactions between selective inhibitors and SVMPs. Comparisons of structures of hemorrhagic and non-hemorrhagic SVMPs revealed different distributions of electric charge on the surface of SVMPs, which may be exploited to design specific inhibitors. The specific inhibitors may also be useful to identify target molecules of the SVMPs and help to understand their mechanism of action.
Narumi Aoki-Shioi; Cho Yeow Koh; R. Manjunatha Kini. Natural Inhibitors of Snake Venom Metalloproteinases. Australian Journal of Chemistry 2020, 73, 277 .
AMA StyleNarumi Aoki-Shioi, Cho Yeow Koh, R. Manjunatha Kini. Natural Inhibitors of Snake Venom Metalloproteinases. Australian Journal of Chemistry. 2020; 73 (4):277.
Chicago/Turabian StyleNarumi Aoki-Shioi; Cho Yeow Koh; R. Manjunatha Kini. 2020. "Natural Inhibitors of Snake Venom Metalloproteinases." Australian Journal of Chemistry 73, no. 4: 277.
According to the World Health Organization, approximately 1.8–2.7 million people worldwide suffer from venomous snake bites each year and at least 138,000 of these incidents are fatal. Whereas, snakebite envenoming poses a serious threat to public health, yet the snake venom toxins endow several pharmacological effects, including presynaptic neurotoxicity, myotoxicity, and cardiotoxicity, as well as anticoagulant, hemolytic, hemorrhagic, edema-inducing, and platelet aggregation-inhibiting effects. Duplication and mutation of the genes encoding these toxins play an important role in generating molecular diversity. Curiously, venomous snakes are not lethal to the viper itself because the viper’s resistance against its own venom. However, endogenous inhibitor proteins evolutionarily acquired by venomous snakes to protect themselves have not yet been fully characterised because it is unclear how to inhibit for target toxin due to the lack of information including mutation analysis and the three-dimensional structures of the inhibitors. This review provides an overview of endogenous inhibitors of venomous snake as regulation systems for the toxin proteins. Recently, we isolated some inhibitors targeting different toxins from the sera of the Japanese vipers. We investigated the evolution of these endogenous inhibitors, which have been significantly influenced by positive selection. Directional mutagenesis, where mutation hotspots are found in genes encoding molecular surface proteins and functional domains of these proteins, acts as a diversifying mechanism for the exquisite biological targeting necessary to protect the host from its own venom.
Narumi Aoki-Shioi. Adaptation and diversification of venomous snake proteins. The Nucleus 2019, 62, 165 -172.
AMA StyleNarumi Aoki-Shioi. Adaptation and diversification of venomous snake proteins. The Nucleus. 2019; 62 (2):165-172.
Chicago/Turabian StyleNarumi Aoki-Shioi. 2019. "Adaptation and diversification of venomous snake proteins." The Nucleus 62, no. 2: 165-172.
Narumi Shioi; Takashi Tadokoro; Yaopeng Hu; Lin Hai Kurahara; Keizo Hiraishi; Katsumi Maenaka; Isao Kuraoka; Shigeyuki Terada. Specificity of endogenous inhibitor for the snake neurotoxin triflin: Interaction and structure analysis. Toxicon 2019, 158, S34 .
AMA StyleNarumi Shioi, Takashi Tadokoro, Yaopeng Hu, Lin Hai Kurahara, Keizo Hiraishi, Katsumi Maenaka, Isao Kuraoka, Shigeyuki Terada. Specificity of endogenous inhibitor for the snake neurotoxin triflin: Interaction and structure analysis. Toxicon. 2019; 158 ():S34.
Chicago/Turabian StyleNarumi Shioi; Takashi Tadokoro; Yaopeng Hu; Lin Hai Kurahara; Keizo Hiraishi; Katsumi Maenaka; Isao Kuraoka; Shigeyuki Terada. 2019. "Specificity of endogenous inhibitor for the snake neurotoxin triflin: Interaction and structure analysis." Toxicon 158, no. : S34.
Venomous snakes have endogenous proteins that neutralize the toxicity of their venom components. We previously identified five small serum proteins (SSP-1–SSP-5) from a highly venomous snake belonging to the family Viperidae as inhibitors of various toxins from snake venom. The endogenous inhibitors belong to the prostate secretory protein of 94 amino acids (PSP94) family. SSP-2 interacts with triflin, which is a member of the cysteine-rich secretory protein (CRISP) family that blocks smooth muscle contraction. However, the structural basis for the interaction and biological roles of these inhibitors is largely unknown. Here, we determined the crystal structure of the SSP-2–triflin complex at 2.3 Å resolution. A concave region centrally located in the N-terminal domain of triflin is fully occupied by the terminal -strands of SSP-2. SSP-2 does not bind tightly to the C-terminal cysteine-rich domain of triflin; this domain is thought to be responsible for its channel-blocker function. Instead, the cysteine-rich domain is tilted 7.7° upon binding to SSP-2, and the inhibitor appears to sterically hinder triflin binding to calcium channels. These results help explain how an endogenous inhibitor prevents the venomous protein from maintaining homeostasis in the host. Furthermore, this interaction also sheds light on the binding interface between the human homologues PSP94 and CRISP-3, which are upregulated in prostate and ovarian cancers.
Narumi Shioi; Takashi Tadokoro; Seijiro Shioi; Yuki Okabe; Haruki Matsubara; Shunsuke Kita; Toyoyuki Ose; Kimiko Kuroki; Shigeyuki Terada; Katsumi Maenaka. Crystal structure of the complex between venom toxin and serum inhibitor from Viperidae snake. Journal of Biological Chemistry 2019, 294, 1250 -1256.
AMA StyleNarumi Shioi, Takashi Tadokoro, Seijiro Shioi, Yuki Okabe, Haruki Matsubara, Shunsuke Kita, Toyoyuki Ose, Kimiko Kuroki, Shigeyuki Terada, Katsumi Maenaka. Crystal structure of the complex between venom toxin and serum inhibitor from Viperidae snake. Journal of Biological Chemistry. 2019; 294 (4):1250-1256.
Chicago/Turabian StyleNarumi Shioi; Takashi Tadokoro; Seijiro Shioi; Yuki Okabe; Haruki Matsubara; Shunsuke Kita; Toyoyuki Ose; Kimiko Kuroki; Shigeyuki Terada; Katsumi Maenaka. 2019. "Crystal structure of the complex between venom toxin and serum inhibitor from Viperidae snake." Journal of Biological Chemistry 294, no. 4: 1250-1256.
A wide variety of DNA lesions interfere with replication and transcription, leading to mutations and cell death. DNA repair mechanisms act upon these DNA lesions present in the genomic DNA. To investigate a DNA repair mechanism elaborately, an in vitro DNA repair substrate containing DNA lesions at a specific site is required. Previously, to prepare the substrate, phagemid ssDNA and DNA lesion-harboring oligonucleotides were employed with considerable amounts of DNA polymerase and DNA ligase. However, preparing in vitro DNA repair substrate in general is difficult and labor intensive. Here, we modified the construction method of in vitro mismatch repair substrate using a nicking-endonuclease, which produces gap corresponding to the ssDNA in the plasmid DNA, and swaps DNA lesion-containing oligonucleotide upon addition of restriction enzyme and T5 exonuclease. This modified method is able to produce in vitro DNA repair substrates containing adenine:cytosine mismatch basepair, 8-oxoG, and uracil. The DNA repair enzyme, each Fpg, hOGG1 could cleave an 8-oxoG-containing DNA substrate, the mixture of UDG and APE1 could cleave a uracil-containing DNA substrate. Omitting a column purification step, DNA repair substrates were prepared by one-pot synthesis. We were able to prepare in vitro DNA repair substrates using this simple method involving restriction enzymes and T5 exonuclease. It is anticipated that this method, termed as “Oligo Swapping Method”, will be valuable for understanding the DNA repair machinery.
Mika Yukutake; Mika Hayashida; Narumi Shioi Aoki; Isao Kuraoka. Oligo swapping method for in vitro DNA repair substrate containing a single DNA lesion at a specific site. Genes and Environment 2018, 40, 23 .
AMA StyleMika Yukutake, Mika Hayashida, Narumi Shioi Aoki, Isao Kuraoka. Oligo swapping method for in vitro DNA repair substrate containing a single DNA lesion at a specific site. Genes and Environment. 2018; 40 (1):23.
Chicago/Turabian StyleMika Yukutake; Mika Hayashida; Narumi Shioi Aoki; Isao Kuraoka. 2018. "Oligo swapping method for in vitro DNA repair substrate containing a single DNA lesion at a specific site." Genes and Environment 40, no. 1: 23.
Some venomous snakes possess anti-toxic proteins in their sera that may play a role in neutralizing the hemorrhagic factors or toxins in their own venom. Five small serum proteins (SSP-1 – SSP-5) were isolated from the serum of Japanese viper (Protobothrops flavoviridis), and were found to act as self-defense proteins against the viper's own toxic components. However, the physiological function of SSP-3 has not been completely elucidated. Affinity chromatography of the venom on an SSP-3-immobilized column identified a novel 55-kDa protein as the target molecule of SSP-3. Sequences of internal fragments of this SSP-3-binding protein showed high homology to those of metalloproteinases from the P. flavoviridis venom. The cDNA sequence revealed that this protein, termed flavorase, is a P-III class metalloproteinase consisting of 423 amino acid residues. The purified protein did not show hemorrhagic and cytotoxic activity. Biacore measurements revealed that SSP-3 was bound to flavorase with a dissociation constant of 6.4 × 10-9 M. SSP-3 non-competitively inhibited the peptidase activity of flavorase with an inhibition constant of 6.6 × 10-9 M.
Narumi Shioi; Ayumi Nishijima; Shigeyuki Terada. Flavorase, a novel non-haemorrhagic metalloproteinase in Protobothrops flavoviridis venom, is a target molecule of small serum protein-3. The Journal of Biochemistry 2015, 158, 37 -48.
AMA StyleNarumi Shioi, Ayumi Nishijima, Shigeyuki Terada. Flavorase, a novel non-haemorrhagic metalloproteinase in Protobothrops flavoviridis venom, is a target molecule of small serum protein-3. The Journal of Biochemistry. 2015; 158 (1):37-48.
Chicago/Turabian StyleNarumi Shioi; Ayumi Nishijima; Shigeyuki Terada. 2015. "Flavorase, a novel non-haemorrhagic metalloproteinase in Protobothrops flavoviridis venom, is a target molecule of small serum protein-3." The Journal of Biochemistry 158, no. 1: 37-48.
Viperidae snakes containing various venomous proteins also have several anti-toxic proteins in their sera. However, the physiological function of serum protein has been elucidated incompletely. Small serum protein (SSP)-1 is a major component of the SSPs isolated from the serum of a Japanese viper, the habu snake (Trimeresurus flavoviridis). It exists in the blood as a binary complex with habu serum factor (HSF), a snake venom metalloproteinase inhibitor. Affinity chromatography of the venom on an SSP-1-immobilized column identified HV1, an apoptosis-inducing metalloproteinase, as the target protein of SSP-1. Biacore measurements revealed that SSP-1 was bound to HV1 with a dissociation constant of 8.2 × 10−8 M. However, SSP-1 did not inhibit the peptidase activity of HV1. Although HSF alone showed no inhibitory activity or binding affinity to HV1, the SSP-1–HSF binary complex bound to HV1 formed a ternary complex that non-competitively inhibited the peptidase activity of HV1 with a inhibition constant of 5.1 ± 1.3 × 10−9 M. The SSP-1–HSF complex also effectively suppressed the apoptosis of vascular endothelial cells and caspase 3 activation induced by HV1. Thus, SSP-1 is a unique protein that non-covalently attaches to HV1 and changes its susceptibility to HSF.
Narumi Shioi; Eiki Ogawa; Yuki Mizukami; Shuhei Abe; Rieko Hayashi; Shigeyuki Terada. Small serum protein-1 changes the susceptibility of an apoptosis-inducing metalloproteinase HV1 to a metalloproteinase inhibitor in habu snake (Trimeresurus flavoviridis). The Journal of Biochemistry 2012, 153, 121 -129.
AMA StyleNarumi Shioi, Eiki Ogawa, Yuki Mizukami, Shuhei Abe, Rieko Hayashi, Shigeyuki Terada. Small serum protein-1 changes the susceptibility of an apoptosis-inducing metalloproteinase HV1 to a metalloproteinase inhibitor in habu snake (Trimeresurus flavoviridis). The Journal of Biochemistry. 2012; 153 (1):121-129.
Chicago/Turabian StyleNarumi Shioi; Eiki Ogawa; Yuki Mizukami; Shuhei Abe; Rieko Hayashi; Shigeyuki Terada. 2012. "Small serum protein-1 changes the susceptibility of an apoptosis-inducing metalloproteinase HV1 to a metalloproteinase inhibitor in habu snake (Trimeresurus flavoviridis)." The Journal of Biochemistry 153, no. 1: 121-129.
Novel proteins were isolated from the sera of Chinese Mamushi (Gloydius blomhoffi brevicaudus) and Habu (Trimeresurus flavoviridis). The primary structures of these proteins were determined by protein sequencing, and the nucleotide sequences were established by cDNA cloning from the liver mRNAs. They belonged to the fetuin family having a double-headed cystatin-like domain and a His-rich domain, akin to HSF, an antihemorrhagic factor isolated from Habu serum. They showed no antihemorrhagic activity and were designated HSF-like proteins (HLPs). Mamushi serum contained two different HLPs termed HLP-A and HLP-B. Both HLP-A and Habu HLP had a unique 17-residue deletion in their His-rich domains. HLP-B comprised two glycosylated polypeptide chains and inhibited the precipitation of calcium phosphate as potently as does bovine fetuin. HLP-B was hence identified as a snake fetuin. The phylogenetic analysis of the fetuin family of proteins showed that antihemorrhagins and HLPs have evolved from this snake fetuin.
Narumi Aoki; Masanobu Deshimaru; Kenji Kihara; Shigeyuki Terada. Snake fetuin: Isolation and structural analysis of new fetuin family proteins from the sera of venomous snakes. Toxicon 2009, 54, 481 -490.
AMA StyleNarumi Aoki, Masanobu Deshimaru, Kenji Kihara, Shigeyuki Terada. Snake fetuin: Isolation and structural analysis of new fetuin family proteins from the sera of venomous snakes. Toxicon. 2009; 54 (4):481-490.
Chicago/Turabian StyleNarumi Aoki; Masanobu Deshimaru; Kenji Kihara; Shigeyuki Terada. 2009. "Snake fetuin: Isolation and structural analysis of new fetuin family proteins from the sera of venomous snakes." Toxicon 54, no. 4: 481-490.
Habu (Trimeresurus flavoviridis) serum contains 3 small serum proteins (SSP-1, SSP-2, and SSP-3) with molecular masses of 6.5 to 10 kDa. Gel filtration analysis showed that all the SSPs exist in high molecular mass forms of approximately 60 kDa in the serum. Ultrafiltration of Habu serum showed that SSPs dissociated from the complex below a pH of 4. An SSP-binding protein was purified from Habu serum by gel filtration, ion exchange, and reverse-phase HPLC. N-terminal sequencing yielded a 39-amino acid sequence, similar to the N-terminal region of triflin, which is a snake venom-derived Ca2+ channel blocker that suppresses smooth muscle contraction. The amino acid sequence of this protein, termed serotriflin, was established by peptide analysis and cDNA cloning. Serotriflin is a glycosylated protein and consists of 221 amino acids. Among the 3 SSPs, only SSP-2 formed a noncovalent complex with serotriflin. It was bound to triflin and serotriflin with high affinity, as evidenced by surface plasmon resonance. SSP-2 is considered to be a protein that prevents self injury by accidental leaking of venom into the blood.
Narumi Aoki; Akie Sakiyama; Kimiko Kuroki; Katsumi Maenaka; Daisuke Kohda; Masanobu Deshimaru; Shigeyuki Terada. Serotriflin, a CRISP family protein with binding affinity for small serum protein-2 in snake serum. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2008, 1784, 621 -628.
AMA StyleNarumi Aoki, Akie Sakiyama, Kimiko Kuroki, Katsumi Maenaka, Daisuke Kohda, Masanobu Deshimaru, Shigeyuki Terada. Serotriflin, a CRISP family protein with binding affinity for small serum protein-2 in snake serum. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics. 2008; 1784 (4):621-628.
Chicago/Turabian StyleNarumi Aoki; Akie Sakiyama; Kimiko Kuroki; Katsumi Maenaka; Daisuke Kohda; Masanobu Deshimaru; Shigeyuki Terada. 2008. "Serotriflin, a CRISP family protein with binding affinity for small serum protein-2 in snake serum." Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 1784, no. 4: 621-628.