Open AccessConversion of the Active‐Site Cysteine Residue of Papain into a Dehydro‐serine, a Serine and a Glycine Residue
Author(s) -
CLARK Peter I.,
LOWE Gordon
Publication year - 1978
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1978.tb12168.x
Subject(s) - papain , chemistry , cysteine , residue (chemistry) , serine , glycine , amino acid , stereochemistry , biochemistry , enzyme
Photolysis of papain which had been inhibited with 2‐bromo‐2′,4′‐dimethoxyacetophenone regenerated papain, but also formed [δSer 25 ]papain (i.e. papain in which the active‐site cysteine residue 25 was replaced by dehydroserine) via the intermediate dehydrocysteine analogue, [δCys 25 ]‐papain. Reduction with sodium borohydride gave [Ser 25 ]papain. Both [Ser 25 ]papain and [δSer 25 ]‐papain had binding properties similar to those of papain, but were devoid of enzymic activity. Their fluorescence properties were also investigated. Incubation of [δSer 25 ]papain at pH 9.0 gave [Gly 25 ]papain.