PROSTAGLANDIN SYNTHASE - STRUCTURE AND FUNCTION

  • Kulmacz, Richard J, (PI)

Project: Research projectResearch Project

Description

Prostaglandin H synthase is a microsomal glycoprotein which exhibits two
distinct catalytic activities: a fatty acid oxygenase and peroxidase. The
fatty acid oxygenase (cyclooxygenase) reaction is the first committed step
in the biosynthesis of prostaglandin (PG) D2, PGE2, PGF2, PGI2 and
thromboxane A2, which collectively make up the bulk of eicosanoids. As for
other fatty acid oxygenases, the cyclooxygenase requires hydroperoxide for
catalytic activity. The eicosanoids derived from PGH2 are involved in a
wide variety of physiological and pathological processes including
inlammation, immune surveillance, sleep induction, stroke, and myocardial
infarction. The overall goal is to determine the reaction mechanisms of the
cyclooxygenase and peroxidase activities of PGH synthase, and the
implications of these mechanisms on the regulation of eicosanoid
biosynthesis. The specific aims are to: a) identify and quantitate the redox centers in
the synthase and establish their roles in catalysis; b) determine the
mechanism of activation of the cyclooxygenase by hydroperoxide; c)
determine the basis for the influence of fatty acid structure on the
hydroperoxide activator requirement of the cyclooxygenase; d) formulate a
mechanism for the inactivation of the cyclooxygenase and peroxidase
activities during catalysis; and e) characterize the subunit structure and
the physical arrangement of the subunits in the synthase, and their
influence on catalytic activity. The methodologies to be employed include: analysis of the cyclooxygenase
and peroxidase activities; protein and polypeptide purification and
characterization: proteolytic digestions and fragment analysis; metal
analysis; UV-vis spectrophotometry; magnetic circular dichroism; and
electron paramagnetic resonance.
StatusFinished
Effective start/end date5/1/824/30/92

Funding

  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health
  • National Institutes of Health: $28,092.00

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Prostaglandin-Endoperoxide Synthases
Oxygenases
Fatty Acids
Eicosanoids
Peroxidase
Biosynthesis
Hydrogen Peroxide
Dichroism
Spectrophotometry
Prostaglandins
Catalysis
Purification
Paramagnetic resonance
Prostaglandins I
Catalyst activity
Prostaglandin H2
Prostaglandin D2
Peptides
Molecular oxygen
Dinoprost

Keywords

  • Medicine(all)
  • Biochemistry, Genetics and Molecular Biology(all)