fulltext.study @t Gmail

Kinetic characterization of cresolase activity of Streptomyces antibioticus tyrosinase

Paper ID Volume ID Publish Year Pages File Format Full-Text
18766 42741 2006 6 PDF Available
Title
Kinetic characterization of cresolase activity of Streptomyces antibioticus tyrosinase
Abstract

Streptomyces antibioticus tyrosinase was purified using PEG-8000/phosphate phase partitioning and ammonium sulfate fractionation between 0 and 60%, rendering a clear and stable enzyme compared with the black one that is usually obtained when only ammonium sulphate fractionation is used, and with a 93% of recovery. This enzyme shows both monophenolase (also termed cresolase) and diphenolase (catecholase) activities, confirming that it is a real tyrosinase. The monophenolase activity was characterized by a lag period, whose duration depends on the substrate concentration, the pH, and the presence of catalytic amounts of o-diphenol. The enzyme showed substrate inhibition for p-cresol, with a KM of 0.97 mM and a Ksi of 23 mM. By increasing the concentration of o-diphenols, it was possible to evaluate the enzyme activation constant, Kact, which showed a value of 0.2 μM. The diphenolase activity was kinetically characterized with 4-methylcathechol, showed an optimal pH at 6.5 and a KM of 1.3 mM.

Keywords
Streptomyces antibioticus; Tyrosinase; PEG-8000; Monophenolase activity; Diphenolase activity; Lag period; p-Cresol; 4-Methylcatechol
First Page Preview
Kinetic characterization of cresolase activity of Streptomyces antibioticus tyrosinase
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Enzyme and Microbial Technology - Volume 39, Issue 1, 1 June 2006, Pages 158–163
Authors
, , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us