Conformational aspects of the biological effect of functional fragments of the p21ras oncoprotein family. 2. Fragment 1-16, various sequences]

The conformational analysis data on active (Val12-Gly13], Asp12-Gly13] and Gly12-Asp13]) and passive (Gly12-Gly13] and Pro12-Gly13]) modifications of the p21ras family oncoproteins are presented. The activating amino acid substitutions are shown to be accompanied by essential changes in the secondary structure, resulted in the 9-16 fragment spiralization. The spatial structure of the 1-9 fragment does not vary for all the predominant forms of the active and passive analogues. The results of the conformational analysis have been used for studying the structural-functional relationships.