CHARACTERIZATION OF SOLUBLE ARTIFICIAL PROTEINS WITH RANDOM SEQUENCES

The structural and catalytic properties of two soluble random proteins , RP3-42 and RP3-45, of 141 amino acid residues were investigated, Alt hough no marked secondary structure was detected by CD spectrum, sedim entation equilibrium and small-angle X-ray scattering studies showed t hat they form an oligomeric structure and are as compact as the molten globule, The random proteins have low but distinct esterase activity; the values of the second-order rate constant for the hydrolysis of p- nitrophenol were 0.78 and 1.39 M-1 s(-1) for RP3-42 and RP3-45, respec tively, The differences in the properties of the random and the native proteins are discussed from the evolutionary point of view, (C) 1998 Federation of European Biochemical Societies.