title: A novel alkalo- and thermostable phospholipase D from Streptomyces olivochromogenes.
abstract: A 60 kDa phospholipase D (PLD) was obtained from Streptomyces olivochromogenes by one-step chromatography on Sepharose CL-6B. Maximal activity was at pH 8 and 75 degrees C and the enzyme was stable from pH 7 to 13 and from 55 to 75 degrees C. Thermal and pH stability with temperature optimum of the enzyme were highest among Streptomyces PLDs reported so far. The activity was Ca(2+)-dependent and enhanced by detergents. The Km and Vmax values for phosphatidylcholine were 0.6 mM and 650 mumol min(-1) mg(-1), respectively. In addition, the enzyme also revealed transphosphatidylation activity, which was optimum at pH 8 and 50 degrees C. The first 15 amino acid residues of the N terminal sequence were ADYTPGAPGIGDPYY, which are significantly different from the other known PLDs. The enzyme may therefore be a novel PLD with potential application in the lipid industry.
authors.affiliation: Department of Pharmacy, College of Pharmacy, Chosun University, Gwangju, 501-759, South Korea.
authors.forename: Jaya Ram
authors.initials: JR
authors.lastname: Simkhada
authors.forename: Hyo Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: So Young
authors.initials: SY
authors.lastname: Jang
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Cho
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Park
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
authors.forename: Jin Cheol
authors.initials: JC
authors.lastname: Yoo
mesh_terms: D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D002853:Chromatography, Liquid; D003067:Coenzymes / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D020536:Enzyme Activators; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010713:Phosphatidylcholines / Q000378:metabolism; D010739:Phospholipase D / Q000737:chemistry* / Q000302:isolation & purification*; D012685:Sepharose / Q000031:analogs & derivatives; D020539:Sequence Analysis, Protein; D013302:Streptomyces / Q000201:enzymology*; D013696:Temperature
chemical_list: D002413:Cations, Divalent; D003067:Coenzymes; D003902:Detergents; D020536:Enzyme Activators; D010713:Phosphatidylcholines; C047264:sepharose CL 6B; D012685:Sepharose; D010739:Phospholipase D; D002118:Calcium