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Chemical modification of a‐mannosidase from Aspergillus sp
Author(s) -
Gaikwad Sushama M.,
IslamKhan M.,
Keskar Sulbha S.
Publication year - 1997
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1111/j.1470-8744.1997.tb00421.x
Subject(s) - chemistry , hydroxylamine , enzyme , chemical modification , histidine , substrate (aquarium) , absorbance , reagent , tryptophan , active site , biochemistry , stereochemistry , organic chemistry , chromatography , biology , amino acid , ecology
Chemical modification of a‐mannosidase from Aspergillus sp. revealed the presence of histidine and tryptophan residues at or near the active site. The enzyme was inactivated by diethyl pyrocarbonate (DEPC) and N ‐bromosuccinimide, with a corresponding increase in absorbance at 240 nm and decrease in absorbance at 280 nm respectively. The substrate p ‐nitrophenyl a‐D‐mannoside protected the enzyme against inactivation by the above reagents, and the DEPC‐inactivated enzyme was re‐activated by hydroxylamine, thus confirming the above results.