Structural characterization of the papaya cysteine proteinases at low pH.

摘要: Current control of gastrointestinal nematodes relies primarily on the use synthetic drugs and encounters serious problems resistance. Oral administration plant cysteine proteinases, known to be capable damaging nematode cuticles, has recently been recommended overcome these problems. This prompted us examine if proteinases like four papaya papain, caricain, chymopapain, glycine endopeptidase that have investigated here can survive acidic pH conditions pepsin degradation. The found undergo, at low pH, a conformational transition instantaneously converts their native forms into molten globules are quite unstable rapidly degraded by pepsin. As shown activity measurements, denatured state which finally results from acid treatment is completely irreversible. It concluded origin may require protected against both denaturation proteolysis effective in gut after oral administration.