Paper Citing NAMD - Abstract
Ling, Zhenmin; Kang, Zhen; Liu, Yi; Liu, Song; Chen, Jian; Du, Guocheng
Improvement of catalytic efficiency and thermostability of recombinant Streptomyces griseus trypsin by introducing artificial peptide
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY, 30:1819-1827, JUN 2014
Streptomyces trypsin is one of the serine proteinases in Streptomyces griseus and acts as a key mediator during cell growth and differentiation. S. griseus trypsin (SGT) could be successfully expressed in Pichia pastoris by engineering the natural propeptide APNP. In this study, the recombinant Exmt with peptide YVEF and the wildtype SGT were comparatively investigated in detail. The recombinant Exmt showed significantly increased thermostability which t(1/2) value was 3.89-fold of that of the SGT at 40 degrees C. Moreover, the catalytic efficiency (referring to the specificity constant, k(cat)/K-m) and pH tolerance of Exmt were also improved. In silico modeling analysis uncovered that introduction of the peptide YVEF resulted in a broadened substrate binding pocket and closer catalytic triad (His(57), Asp(102) and Ser(195)). The intramolecular Hydrogen bonds and the cation pi-interactions were also dramatically increased. The results indicated that engineering of the N-terminus with artificial peptides might be an effective approach for optimizing the properties of the target enzymes.
