Proteins protolysis

All viral proteins are cleavage products, most functions regulated by protolysis. Viral protease identified, which processes coat precursor. 

Fig. 7 Chromogenic enzyme assays (A) pyroGlu-Pro-Arg-pNA is a peptide substrate for activated protein C and tissue factor XIa. Protolysis releases the chromophore pora-nitroaniline (pNA), which is monitored by absorbance measurement at 405 nm. (B) ortho-Nitrophenyl-o-galactopyranoside (oNPG) is an artificial substrate for galactosidase that metabolizes lactose. The cleavage of oNPG releases the yellow ortho-nitrophe-nol with maximum absorbance at 420 nm.

Hydrolysis and protolysis have also been shown to be responsible for the absorption maxima observed in the alkaline range with proteins (9b) and polypeptides having a side chain amino group (10,18), and in the acid range with proteins. These maxima were first attributed to conformational equilibria (see paragraph 3). From the relaxation spectra for polylysine and polyornithine (10,18), koH values of about 10 9 s were obtained, i.e.,... 

Scheme 1. Flavin and Flavocoenzyme nomenclature and modes of breakdown by mild and strong protolysis, photolysis and hydrogenolysis (R = H Loosely bound R = Protein [His, Cys] Covalently bound flavin)...

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