title: Cellular localization and detergent dependent oligomerization of rice allene oxide synthase-1.
abstract: Allene oxide synthase-1 from Oryza sativa (OsAOS1) localizes to the chloroplast, but lacks a putative chloroplast targeting sequence typically found in dicot AOS. Here, kinetic parameters and the oligomerization state/subunit composition of OsAOS1 were characterized in vitro in the absence or presence of detergent micelles. The catalytic efficiency (k(cat)/K(m)) of OsAOS1 reached a maximum near the critical micelle concentration for polyoxyethylene 10 tridecyl ether. Native gel analysis showed that OsAOS1 exists as a multimer in the absence of detergent micelles. The multimeric form of OsAOS1 was stably cross-linked in the absence of detergents, while only monomeric OsAOS1 was detected in the presence of detergent micelles. Gel filtration analysis indicated that the oligomeric state of OsAOS1 depends strongly on the detergents and that the monomer becomes the predominant form in the presence of detergent micelles. These data suggest that the detergent-dependent oligomeric state of OsAOS1 is an important factor for the regulation of its catalytic efficiency.
authors.affiliation: Department of Molecular Biotechnology and Kumho Life Science Laboratory, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 500-757, Republic of Korea.
authors.forename: Sereyvath
authors.initials: S
authors.lastname: Yoeun
authors.forename: Jeong-Il
authors.initials: JI
authors.lastname: Kim
authors.forename: Oksoo
authors.initials: O
authors.lastname: Han
mesh_terms: D000595:Amino Acid Sequence; D055162:Biocatalysis / Q000187:drug effects; D002850:Chromatography, Gel; D003902:Detergents / Q000494:pharmacology*; D019746:Intramolecular Oxidoreductases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012275:Oryza / Q000166:cytology* / Q000201:enzymology*; D010802:Phylogeny; D018515:Plant Leaves / Q000187:drug effects / Q000201:enzymology; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism*; D055503:Protein Multimerization / Q000187:drug effects*; D021381:Protein Transport / Q000187:drug effects
chemical_list: D003902:Detergents; D010940:Plant Proteins; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase