title: A novel Ca2+-dependent phospholipase D from Streptomyces tendae, possessing only hydrolytic activity.
abstract: An extracellular phospholipase D (PLD(St)) was purified from Streptomyces tendae by two successive chromatographic steps on Sepharose CL-6B and DEAE-Sepharose CL-6B. Molecular weight of the PLD(St) was estimated to be approximately 43 kDa by sodium dodecyl sulfatepolyacrylamide gel electrophoresis. Maximal activity was at pH 8 and 60 degrees C, and the enzyme was stable at or below 60 degrees C and between pH 8 and 10, when assayed after 1.5 and 24 h, respectively. The enzyme activity had an absolute requirement of Ca(2+), and the maximum activity was at 2 mM CaCl(2). The Km and Vmax values for phosphatidyl choline were 0.95 mM and 810 micromol min(-1) mg(-1), respectively. More importantly, PLD(St) could not catalyze transphosphatidylation of glycerol, L-serine, myo-inositol and ethanolamine, which have been extensively used to evaluate the activity. The result strongly suggests that PLD( St ) does not have the transphosphatidylation activity, thereby making it the first Streptomyces PLD possessing only hydrolytic activity. PLD(St) may therefore be a novel type of PLD enzyme.
authors.affiliation: Department of Pharmacy, College of Pharmacy, Chosun University, Gwangju, Korea.
authors.forename: Poonam
authors.initials: P
authors.lastname: Mander
authors.forename: Jaya Ram
authors.initials: JR
authors.lastname: Simkhada
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Cho
authors.forename: Sung Ju
authors.initials: SJ
authors.lastname: Park
authors.forename: Hong Seok
authors.initials: HS
authors.lastname: Choi
authors.forename: Hei Chan
authors.initials: HC
authors.lastname: Lee
authors.forename: Jae Kyung
authors.initials: JK
authors.lastname: Sohng
authors.forename: Jin Cheol
authors.initials: JC
authors.lastname: Yoo
mesh_terms: D002122:Calcium Chloride / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D010713:Phosphatidylcholines / Q000737:chemistry; D010739:Phospholipase D / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology*; D013696:Temperature
chemical_list: D010713:Phosphatidylcholines; D010739:Phospholipase D; D002122:Calcium Chloride