The thiolesterase activity of sulfhydryl-activated enzymes: A new assay for thiol proteases based on activation by Sepharose-bound mercaptan
✍ Scribed by Robert M. Metrione
- Publisher
- Elsevier Science
- Year
- 1981
- Tongue
- English
- Weight
- 506 KB
- Volume
- 110
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
It has been shown that sulthydryl enzymes can be activated in a two-phase system by mercaptans which are coupled to Sepharose beads. Such an activator permits the use of thiol esters as substrates for enzymes requiring mercaptan activators, since the activator mercaptan and product mercaptan are easily separated by centrifugation or filtration before analysis. An assay for cathepsin B using benzyloxycarbony-Lys-thiobenzyl ester as a substrate and glutathione coupled to Sepharose as an activator, has been shown to be 275 times as sensitive as a standard assay using benzoyl-DL-arginine-P-nitroanilide.
For papain, the thiol esterase assay is 162 times as sensitive as the bC!IZOyl-DL-RQiIIk+Pnitroanilide assay. A comparison of the advantages and disadvantages of this assay is included.