title: Purification and characterization of protein methylase II from Helicobacter pylori.
abstract: Protein methylase II (AdoMet:protein-carboxyl O-methyltransferase, EC 2.1.1.24) was identified and purified 115-fold from Helicobacter pylori through Q-Sepharose ion exchange column, AdoHcy-Sepharose 4B column, and Superdex 200 HR column chromatography using FPLC. The purified preparation showed two protein bands of about 78 kDa and 29 kDa molecular mass on SDS-PAGE. On non-denaturing gel electrophoresis, the enzyme migrated as a single band with a molecular mass of 410 kDa. In addition, MALDI-TOF-MS analysis and Superdex 200 HR column chromatography of the purified enzyme showed a major mass signal with molecular mass values of 425 kDa and 430 kDa, respectively. Therefore, the above results led us to suggest that protein methylase II purified from H. pylori is composed of four heterodimers with 425 kDa (4x(78+29)=428 kDa). This magnitude of molecular mass is unusual for protein methylases II so far reported. The enzyme has an optimal pH of 6.0, a K(m) value of 5.0x10(-6) M for S-adenosyl-L-methionine and a V(max) of 205 pmol methyl-(14)C transferred min(-1) mg(-1) protein.
authors.affiliation: Department of Pharmacy, College of Pharmacy, Sungkyunkwan University, Suwon, South Korea.
authors.forename: Y M
authors.initials: YM
authors.lastname: Kim
authors.forename: S H
authors.initials: SH
authors.lastname: Ahn
authors.forename: D W
authors.initials: DW
authors.lastname: Seo
authors.forename: Y K
authors.initials: YK
authors.lastname: Kim
authors.forename: J W
authors.initials: JW
authors.lastname: Han
authors.forename: S
authors.initials: S
authors.lastname: Hong
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: W K
authors.initials: WK
authors.lastname: Paik
authors.forename: H W
authors.initials: HW
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D016481:Helicobacter Infections / Q000382:microbiology; D016480:Helicobacter pylori / Q000201:enzymology*; D006801:Humans; D008969:Molecular Sequence Data; D011497:Protein O-Methyltransferase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D011497:Protein O-Methyltransferase