| Literature DB >> 16321357 |
Monika Mortimer1, Reet Järving, Alan R Brash, Nigulas Samel, Ivar Järving.
Abstract
11R-Lipoxygenase (11R-LOX) activity has been detected in several marine invertebrates, and here we report the first cloning and expression of the enzyme. The cDNA encoding a protein of 77kDa was isolated by RT-PCR from the soft coral Gersemia fruticosa and expressed in Escherichia coli. Incubations of recombinant enzyme with arachidonic acid yielded a single product, identified by RP-HPLC, GC-MS, and chiral phase-HPLC as 11R-hydroperoxyeicosatetraenoic acid. Other C18, C20, and C22 substrates are also oxygenated, preferentially at the omega10 position. Significantly, both Ca(2+)-ions and a membrane fraction are required for catalytic activity. Calcium effects translocation of the soluble 11R-LOX to the membrane and this association is reversible by Ca(2+) chelation. The enzyme sequence contains some conserved amino acids implicated in calcium activation of mammalian 5-LOX, and with its obligate requirement for membrane interaction the 11R-LOX may thus provide a new model for further analysis of this aspect of lipoxygenase activation.Entities:
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Year: 2005 PMID： 16321357 DOI： 10.1016/j.abb.2005.10.023
Source DB: PubMed Journal: Arch Biochem Biophys ISSN： 0003-9861 Impact factor: 4.013