Bacillus thuringiensis is a Gram-positive soil bacterium known as biopesticide bacteria that produce insecticidal proteins called protein crystals (Cry). In the process of insecticides, chitinase advisable to perforate the membrane barrier peritrophic to facilitate the invasion of Cry proteins to the membrane epithelium. A chitinase gene from B. thuringiensis successfully expressed in soluble form in Escherichia coli and purified and characterized the gene product. Purified recombinant enzyme, BthChi74, hydrolyzed artificial substrates, 4-nitrophenyl N, N'-diacetyl-β-D-chitobioside [4NP- (GlcNAc) 2], and the natural substrate, colloidal chitin and crystal α-chitin, but it does not hydrolyze cellulose. BthChi74 shows the catalytic activity under weakly acidic to neutral pH Yeast Recombinant Proteins range at 50 ° C, and it was stable at broad pH range for 24 hours. Differential scanning Uranium (DSF) shows the protein melting temperature (T m) of 63.6 ° C. The kin...
Heterologous expression, purification and biochemical characterization of a glutamate racemase (MurI) from Streptococcus mutans UA159.
Background Glutamate racemase (MURI) is a cofactor-independent enzyme which is essential for bacterial peptidoglycan biosynthesis pathway and therefore has been considered an attractive target for antimicrobial drug development. While in our previous study of gene essentiality MURI indicated Streptococcus mutans, a metiologicalajor agent of human Purified Recombiant Proteins dental caries, the study of S. mutans Muri not provide definitive results. This study aims to produce and characterize the biochemical properties of S. mutans UA159 Muri of the genome. method Structural characterization and prediction of multiple sequence alignment performed by bioinformatics analysis. Ilis6-tagged recombinant S. mutans MURI was expressed in pColdII expression vector and further purified using Ni 2+ affinity chromatography. protein solubility, purity and the state of aggregation were analyzed by SDS-PAGE, Western blotting, native PAGE and SEC-HPLC. assay kinetic parameters assessed by ci...