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Effects of high pressure on papain activity and structure
Author(s) -
Gomes Maria Regina A,
Sumner Ian G,
Ledward Dave A
Publication year - 1997
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/(sici)1097-0010(199709)75:1<67::aid-jsfa843>3.0.co;2-q
Subject(s) - papain , chemistry , phosphate , oxygen pressure , tris , electrophoresis , phosphate buffered saline , chromatography , oxygen , enzyme , biochemistry , organic chemistry
Papain was progressively inactivated by increasing pressures in both phosphate (pH 5·0 and 6·8) and Tris (pH 6·8) buffer, but in all systems the effect at pressures up to 600 MPa was minimal and independent of the temperature. However, at 800 MPa, significant losses were found. These losses at 800 MPa were more marked when pressure treatment was at 60°C than when at 20°C. Even though inactivation occurred at 800 MPa, electrophoretic and calorimetric analysis indicated there was little change in size or conformation of the enzyme. The loss in activity, though, was very dependent on the oxygen concentration during pressure treatment, and it is suggested that oxidation of the thiolate ion at the active site, to SO 2 − or SO 3 − , is the major reason for the pressure inactivation of papain. © 1997 SCI.