Open AccessCharacterization of proteolytic activity associated with Bacillus thuringiensis var. darmstadiensis crystals
Author(s) -
Thurley P.,
Chilcott C.N.,
Kalmakoff J.,
Pillai J.S.
Publication year - 1985
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1985.tb00671.x
Subject(s) - protease , iodoacetic acid , pmsf , bacillus thuringiensis , ethylenediamine , enzyme , bacillales , biochemistry , bacillaceae , chemistry , biology , bacteria , organic chemistry , bacillus subtilis , genetics
14 C‐labelled Bacillus thuringiensis var. darmstadiensis (Btd) crystals were used to detect crystal‐associated protease activity. Optimal protease activity occurred at pH 8.4 and 9.7, and at 15 and 35°C. Protease activity was destroyed by heating the crystals at 121°C for 15 min. Cellular enzymes from Btd did not solubilise Btd crystals. Iodoacetic acid (50 mM) caused a 20% reduction in protease activity while phenylmethyl‐sulphonylfluoride (PMSF), ethylenediamine‐tetraacetic acid (EDTA) and p ‐chloromercuribenzene (PCMB) had no inhibitory effect on protease activity.