SYNTHESIS OF NEW CHROMOGENIC SUBSTRATES F OR ASPARTYL PROTEASES

A general method was developed for the synthesis of new chromogenic su bstrates of aspartyl proteases: Dnp-Ala-Xaa-Phe-Phe-Ala-Arg-NH2, where Xaa was Ala or Ser. The synthetic scheme involved both chemical and e nzymic stages, the condensation of tripeptides in an organic medium by means of pepsin immobilized on Celite being among the latters. The in fluence of organic solvents, reaction time, and the composition and io nic strength of the buffers used in the reaction mixture and at the pe psin immobilization step on the efficacy of the pepsin-catalyzed synth esis was studied.