Recombinant Human rhinovirus 3C protease [His, GST]

Monophenyl and diphenyl pseudoxazolone derivatives of glycine and alanine were prepared and found to be time-dependent inhibitors of hepatitis A virus (HAV) 3C and human rhinovirus (HRV) 3C proteinases with IC50 values in the micromolar range.

To simplify purification and improve heat tolerance of a thermostable /beta-xylosidase (ThXy1C), a short ELK16 peptide was attached to its C-terminus, which is designated as ThXy1C ELK. Wild-type ThXy1C was normally expressed in soluble form. However, ThXy1C ELK assembled into aggregates with 98.6% of total beta-xylosidase activity. After simple centrifugation and buffer washing, the ThXy1C ELK particles were collected with 92.57% activity recovery and 95% purity, respectively. Meanwhile, the wild-type ThXy1C recovery yield was less than 55% after heat inactivation, affinity and desalting chromatography followed by HRV 3C protease cleavage purification. Catalytic efficiency (K-cat/K-m) was increased from 21.31 mM(-1) s(-1) for ThXy1C to 32.19 mM(-1) s(-1) for ThXy1C ELK accompanied by a small increase in K-m value. Heat tolerance of ThXy1C ELK at high temperatures was also increased. The ELK16 peptide attachment resulted in 6.2-fold increase of half-life at 65 degrees C. Released reducing sugars were raised 1.3-fold during sugar cane bagasse hydrolysis when ThXy1C-ELK was supplemented into the combination of XynA Delta SLH and Cellic CTec2.