Artemisinin (also known as Qinghaosu), an active component of the Qinghao extract, is widely used as antimalarial drug. Previous studies reveal that artemisinin and its derivatives also have effective anti-inflammatory and immunomodulatory properties, but the direct molecular target remains unknown. Recently, several reports mentioned that myeloid differentiation factor 2 (MD-2, also known as lymphocyte antigen 96) may be the endogenous target of artemisinin in the inhibition of lipopolysaccharide signaling. However, the exact interaction between artemisinin and MD-2 is still not fully understood. Here, experimental and computational methods were employed to elucidate the relationship between the artemisinin and its inhibition mechanism. Experimental results showed that artemether exhibit higher anti-inflammatory activity performance than artemisinin and artesunate. Molecular docking results showed that artemisinin, artesunate, and artemether had similar binding poses, and all complexes remained stable throughout the whole molecular dynamics simulations, whereas the binding of artemisinin and its derivatives to MD-2 decreased the TLR4(Toll-Like Receptor 4)/MD-2 stability. Moreover, artemether exhibited lower binding energy as compared to artemisinin and artesunate, which is in good agreement with the experimental results. Leu61, Leu78, and Ile117 are indeed key residues that contribute to the binding free energy. Binding free energy analysis further confirmed that hydrophobic interactions were critical to maintain the binding mode of artemisinin and its derivatives with MD-2.
1 August 2021 in Protein Expression and Purification
Traditional methods for single-nucleotide variants based on amplification and fluorescence signals require expensive reagents and cumbersome instruments, and they are time-consuming for each trial. Here, a porous anodised aluminium (PAA)-based sensing chip modified with deactivated Cas9 (dCas9) proteins and synthetic guide RNA (sgRNA) as the biorecognition receptor is developed, which can be used for the label-free sensing of the diffuse large B-cell lymphoma (DLBCL) MYD88L265P gene by integrating with electrochemical ionic current rectification (ICR) measurement. The sgRNA that can specifically identify and capture the MYD88L265P gene was screened, which has been proved to be workable to activate dCas9 for the target MYD88L265P. In the sensing process, the dCas9 proteins can capture the genome sequence, thus bringing negative charges over the PAA chip and correspondingly resulting in a variation in the ICR value due to the uneven transport of potassium anions through the ion channels of the PAA chip. The whole sensing can be finished within 40 min, and there is no need for gene amplification. The CRISPR/dCas9-based sensor demonstrates ultrasensitive detection performance in the concentration range of 50 to 200 ng μL−1 and it has been proved to be feasible for the genome sequence of patient tissues. This sensor shows the potential of targeting other mutations by designing the corresponding sgRNAs and expands the applications of CRISPR/dCas9 technology to the on-chip electrical detection of nucleic acids, which will be very valuable for rapid diagnosis of clinically mutated genes. This makes the hybrid CRISPR–PAA chip an ideal candidate for next-generation nucleic acid biosensors.
Ganoderma lucidum, also known as LINGZHI, has a long tradition of use in folk medicine of the Far East, which is documented in the oldest Chinese pharmacopoeia, declaring it a superior medicine. LINGZHI-8 (LZ-8) is an immunoregulatory fungal protein isolated from the fruiting body of Ganoderma lucidum. Neutropenia is a condition with an abnormally low levels of neutrophils in the blood, which is caused by numerous medical conditions or medications, such as chemotherapy. The current study demonstrated that recombinant LZ-8 (rLZ-8) from Pichia promoted the differentiation of bone marrow hematopoietic stem cells (HSCs) into granulocytes in a neutropenia mouse model induced by cyclophosphamide. Also, it regulated the CXCR4-SDF1 axis to promote the mobilization of HSCs and the release of neutrophils from the bone marrow to peripheral blood. Binding of rLZ-8 to the colony stimulating factor 1 receptor (CSF1R) promotes the differentiation of HSCs into primitive CFU colonies. These results suggested that rLZ-8 has a potential effect in the treatment of chemotherapy-induced neutropenia.
The precise role of Epidermal Growth Factor Receptor (EGFR) in Hepatocellular carcinoma (HCC) cells is unknown and EGFR inhibitors have not achieved positive clinical results. The rapid and drastic internalization of EGFR has been proved to successfully treat EGFR inhibitor-resistant patients in recent clinical trials. Here, the anti-tumor efficacy of a protein (rLZ-8) from Ganoderma lucidum was evaluated, it was demonstrated that rLZ-8 could bind to EGFR specifically, drastically enter into Hepatoma cells, abrogate endosomal recycling and induce HCC cell death. Surprisingly, we screened a monoclonal antibody which possesses competitive binding site with rLZ-8, it also trigger catastrophic EGFR internalization. This result suggests that it is necessary to investigate the interface of EGFR and rLZ-8 complex. An internalization related epitope (S222/K269) was identified on the dimerization arm of EGFR extracellular domain (ECD). These results suggest vulnerability of HCC cells to catastrophic EGFR internalization that can be targeted by a novel epitope and point to the possible exploitation in the design of anti-EGFR therapeutic biologics for HCC therapy.