Evidence for mutual exclusion in the tryptic hydrolysis of two peptide bonds in maleylated trypsinogen.

Treatment of completely maleylated trypsinogen with trypsin resulted in a mutual exclusion of hydrolysis of the two arginyl peptide bonds wherein one half of the molecules of the modified zymogen were cleaved at the Arg55-Leu56 bond and the other half of the molecules were cleaved at the Arg105- Val106 bond and no molecules were cleaved at both arginyl bonds.