Protein and Peptide Letters - Volume 22, Issue 1, 2015

Acyltransferases (ATs) play an essential role in the polyketide biosynthesis through transferring acyl units into acyl carrier proteins (ACPs) via a self-acylation reaction and a transacylation reaction. Here we used AT10FkbA of FK506 biosynthetic polyketide synthase (PKS) from Streptomyces tsukubaensis YN06 as a model to study the specificity of ATs for acyl units. Our results show that AT10FkbA can form both malonyl-O-AT1 Read More

Porins are integral membrane proteins found in the outer membrane of bacteria, mitochondria and chloroplasts. Herein, we have reviewed sequence and structural understanding about bacterial porins. The first porin structure from Rhodobacter capsulatus at 1.8 Å resolution in 1991 till the recent structural advancement, coupled by immunological properties, diffusion and ion permeation has been taken into account In t Read More

Firefly luciferase is a relatively unstable protein and commonly loses its activity at room temperature because of structural changes. The structural and functional stability of this protein is critical for its enzymatic applications. Different approaches are applied to increase the stability of this enzyme such as designing of covalent cross-links (disulfide bonds). In this study, luciferase mutants containing one or two disulfide bond Read More

The human B12 trafficking chaperone protein hCblC is responsible for escorted delivery and early processing of B12 in intracellular B12 metabolism. In this study, we characterized a putative B12 trafficking chaperone of Caenorhabditis elegans (cCblC), which shows 26% amino acid sequence identity with hCblC. cCblC was shown to bind B12 with a broad specificity for the upper axial ligand, as previously observed wit Read More

The genome sequence analysis of Bacillus thuringiensis serovar konkukian S4 has shown to contain two chitinases (Chi74, Chi39) and two chitin-binding proteins (CBP50 and CBP24). The Chi74, Chi39 and CBP50 have been characterized previously. The chitin-binding protein CBP24 was cloned and heterologously expressed in Escherichia coli. The recombinant protein was purified using a Ni-NTA purification system. The purified Read More

The pH stability of lectin from black turtle bean was characterized by a variety of biophysical techniques over the pH range from 2.0 to 10.0. The zero-order and second-derivative UV spectra at different pH values indicated that the tertiary structure of the protein does not change significantly with changes in pH. The maxima emission fluorescence of the lectin upon excitation at 280 nm and 295 nm were found to be blue shifte Read More

An inducible and aromatic nitrilase from Gordonia terrae was purified with a yield of 19%. The enzyme had turnover number of 63 s-1x 10-3, Km 1.4 mM and Vmax 95 Umg-1 protein for benzonitrile. The nitrilase of G. terrae was active at basic pH (7-10), moderate temperature (20-45 °C) and has a half-life of 4 h at 35 °C. MALDI analysis and amino acid sequence deduced from cloned nucleotide fragment showed 97% homolog Read More

Elevated cadmium (Cd) concentrations in fishery byproducts are an environmental concern, that might be reduced by enzymatic removal and adsorption of the contaminants during recycling the byproducts as animal food. We cloned the gene for Arthrobacter nicotinovorans serine protease (ANISEP), which was isolated from the hepatopancreas of the Japanese scallop (Patiopecten yessoensis) and has been found to Read More

Shrimp ovarian peritrophin (SOP), a major protein in jelly layer and cortical rods, plays a role in egg protection after spawning. Previous study, sequence of SOP gene from Fenneropenaeus merguiensis (Fm-SOP) was composed of domain A and domain B. The SOP domain A contains amino acid sequences between 1-80 of Fm-SOP. The domain A had six conserved cysteines which have been found in many antimicrobial pepti Read More

Many proteins in chloroplast are regulated through the disulfide bond/thiol transformation to realize their activities. A homologue of VKOR (Vitamin K epoxide reductase) in Arabidopsis chloroplast is found to catalyze the disulfide bond formation in vivo and to mediate the specific phylloquinone reduction in vitro. It is also called LTO1 (Lumen Thiol Oxidoreductase 1). Investigations about functions and essential amino acid residues Read More

Accumulation of ordered protein aggregates (or amyloids) represents a hallmark of many diseases (e.g., Alzheimer’s disease, type II diabetes, Parkinson’s diseases etc.), results from intermolecular association of partially unfolded proteins/ peptides. Such associations usually take place in highly crowded conditions. The aggregates, which are formed under in vitro and in vivo conditions exhibit substantial variations in their s Read More

G protein-coupled receptors (GPCRs) perform vital signaling functions and are involved in various diseases, making GPCRs major drug targets. GPCRs have seven α-helical transmembrane domains connected by three extracellular loops (ECLs) and three intracellular loops (ICLs). Among the three ICLs, ICL3 has been reported to have a critical function in interacting with downstream signaling molecules. Despite its important r Read More