Evidence for dynamically determined conformational states in rhodanese catalysis.
نویسندگان
چکیده
منابع مشابه
An expanded mechanism for rhodanese catalysis.
The kinetic behavior of rhodanese (thiosulfate: cyanide sulfurtransferase, EC 2.8.1.1) was investigated at pH values from 5.0 to 10.8. The binding of thiosulfate was shown to be dependent upon a pK’ of 9.9, with the protonated enzyme binding the substrate much more strongly than the deprotonated form. An enzymic nucleophile displaces sulfite to form the sulfur-substituted enzyme. This reaction ...
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The enzyme rhodanese is greatly stabilized in the range pH 4-6, and samples at pH 5 are fully active after several days at 23 degrees C. This is very different from results at pH greater than 7, where there is significant loss of activity within 1 h. A pH-dependent conformational change occurs below pH 4 in a transition centered around pH 3.25 that leads slowly to inactive rhodanese at pH 3 (t ...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1985
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)89427-3