The need for rapidly developed diagnostic tests has gained significant attention after the recent pandemic. Production of neutralizing antibodies for vaccine development or antibodies to be used in diagnostic tests usually require the usage of recombinant proteins representing the infectious agent. However, peptides that can mimic these recombinant proteins may be rapidly utilized, especially in emergencies such as the recent outbreak. Here, we report two peptides that mimic the receptor binding domain of the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and investigate their binding behavior against the corresponding human immunoglobulin G and immunoglobulin M (IgG and IgM) antibodies in a clinical sample using a quartz crystal microbalance (QCM) sensor. These peptides were immobilized on a QCM sensor surface, and their binding behavior was studied against a clinical serum sample that was previously determined to be IgG and IgM-positive. It was determined that designed peptides bind to SARS-CoV-2 antibodies in a clinical sample. These peptides might be useful for the detection of SARS-CoV-2 antibodies using different methods such as enzyme-linked immunosorbent assay (ELISA) or lateral flow assays. A similar platform might prove to be useful for the detection and development of antibodies in other infections.

In December 2019 a novel coronavirus was detected in Wuhan City of Hubei Province-China. Owing to a high rate of transmission from human to human, the new virus called SARS-CoV-2 differed from others by its unexpectedly rapid spread. The World Health Organization (WHO) described the most recent coronavirus epidemic as a global pandemic in March 2020. The virus spread triggered a health crisis (the COVID-19 disease) within three months, with socioeconomic implications. No approved targeted-therapies are available for COVID-19, yet. However, it is foreseen that antibody-based treatments may provide an immediate cure for patients. Current neutralizing antibody development studies primarily target the S protein among the structural elements of SARS-CoV-2, which mediates the cell entry of the virus through the angiotensin converting enzyme 2 (ACE2) receptor of host cells. This review aims to provide some of the neutralizing antibody development strategies for SARS-CoV-2 and in vitro and in vivo neutralization assays.

Multiple sclerosis (MS) is a common autoimmune disease that primarily affects young adults. In this condition, the immune system attacks the myelin sheath of nerve cells, leading to a variety of neurological symptoms.

Polyethylene terephthalate (PET), a highly persistent and challenging-to-recycle material, poses a very concerning threat to the environment due to is over accumulation. To combat this issue, we focus on PETase, a biomolecule with immense potential for PET recycling due to its exceptional activity and substrate specificity compared to other PET-degrading enzymes. In this study, the overexpression of IsPETase from Ideonella sakaiensis, was investigated by optimizing its codon usage, cloning it into the pET plasmid, and successfully expressing it in the cytoplasm of Escherichia coli using SHuffle cells, which facilitate the expression of proteins requiring disulfide bonds for proper folding and functionality. Under the optimized conditions, the Shuffle expression system yielded an average of 69.3 mg of IsPETase, with an uncertainty of ±16.8 mg (n = 3), in 1-L culture. This represents an impressive 11.5-fold increase compared to its conventional expression in E. coli. After production, we confirmed the identity of the PETase enzyme using a bottom-up proteomics approach, achieving an impressive 97% coverage and identifying 21 unique peptides. Our research findings were strengthened through additional investigations utilizing High-Resolution Liquid Chromatography-Mass Spectrometry (HR-LC/MS) and Scanning Electron Microscopy (SEM). These analyses confirmed the active production of the PETase in the E. coli SHuffle cells, and its effective PET depolymerization. The application of HR-LC/MS allowed us to quantitatively monitor PETase activity, providing a distinctive approach for future PET recycling and enzyme engineering studies. Overall, our research presents a promising solution to the efficient production of active IsPETase enzyme.