Biosynthetic Pathway of Marine Prostanoids Promoted by Non-cyclooxygenase Biosynthetic Enzyme.

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16550147
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Chemistry related to living body
• Research Institution: Tokyo University of Pharmacy and Life Sciences
• Principal Investigator: WATANABE Kinzo Tokyo University of Pharmacy and Life Sciences, School of Life Sciences, Associate Professor, 生命科学部, 助教授 (10167116)
• Project Period (FY): 2004 – 2005
• Keywords: prostaglandin / biosynthetic pathway / soft coral / Clavularia viridis / lipoxygenase

Research Abstract

The Okinawan soft coral Clavularia viridis is a rich natural source of anti-tumor prostaglandins, clavulones. Corey et al. suggested that the prostaglandin biosynthesis of clavulones could occur through 8-lipoxygenase (8-LOX) pathway. In this study, the biosynthetic intermediates from arachidonic acid using an acetone powder from the living coral, and detected 8-hydroperoxyeicosatetraenoic acid and preclavulone-A were investigated. These biosynthetic intermediates were characterized by HPLC and NMR, and were found to be each enantiomeric in a ratio of 3:1 and 1:1, respectively. cDNA for the key enzyme of the 8-LOX pathway was isolated using degenerate origonucleotides which were designed based on conserved amino acid sequences of LOX proteins. The obtained cDNA encodes a protein of 1066 amino acids, which include an allene oxide synthase (AOS) domain in addition to a LOX domain. The deduced amino acid sequence shares high similarity to that of AOS-8R-LOX fusion protein from the Caribbean soft coral, Plexaura homomalla, cDNA of which was cloned by Brash et al. These results suggest a legitimacy of the proposed Corey's biosynthetic pathway.