NDLI: Isolation and characterization of thromboxane synthase from human platelets as a cytochrome P-450 enzyme.

Please wait, while we are loading the content...

Isolation and characterization of thromboxane synthase from human platelets as a cytochrome P-450 enzyme.

Content Provider	Semantic Scholar
Author	Haurand, Michael Ullrich, Volker
Copyright Year	1985
Abstract	Thromboxane synthase from human platelets was purified to apparent homogeneity by conventional chromatographic techniques. A 423-fold enrichment over the specific content in the 100,000 X g sediment from platelet homogenates was obtained. The enzyme gave a single band on sodium dodecyl sulfate-gel electrophoresis corresponding to a monomeric molecular weight of 58,800. One heme per polypeptide chain was present, and by optical and EPR spectroscopy a close analogy to the group of cytochrome P-450 proteins was established. From its substrate prostaglandin H2, the stable end product thromboxane B2 is formed with a specific activity of 24.1 mumol min-1 mg of protein-1 which corresponds to a molecular activity of 1628 min-1. The enzyme formed 12L-hydroxy-5,8,10-heptadecatrienoic acid together with thromboxane B2 in a 1:1 ratio. Both products were identified by gas chromatography-mass spectrometry analysis. As reported previously for platelet microsomes (Ullrich, V., and Haurand, M. (1983) Adv. Prostaglandin Thromboxane Leukotriene Res. 11, 105-110), the pure hemoprotein spectrally interacts with pyridine- or imidazole-based inhibitors and for the potent inhibitor imidazo-(1,5-a)pyridine-5-hexanoic acid a stoichiometric binding to the heme was shown. Substrate analogs with a methylene group replacing the oxygen in either the 9- or 11-position caused difference spectra showing spectral shifts towards 387 and 407 nm, respectively. The identification of thromboxane synthase as a P-450 protein suggests that the heme-thiolate group of the enzyme is required to split and activate the endoperoxide bond of prostaglandin H2.
File Format	PDF HTM / HTML
PubMed reference number	2999104
Journal	Medline
Volume Number	260
Issue Number	28
Alternate Webpage(s)	http://www.jbc.org/content/260/28/15059.full.pdf
Journal	The Journal of biological chemistry
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in