Open AccessPurification and characterization of protein methylase II from Helicobacter pylori
Author(s) -
Kim Young Man,
Ahn Seong Hoon,
Seo Dong Wan,
Kim Yong Kee,
Han Jeung Whan,
Hong Sungyoul,
Kim Sangduk,
Paik Woon Ki,
Lee Hyang Woo
Publication year - 2001
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2001.tb10497.x
Subject(s) - molecular mass , fast protein liquid chromatography , enzyme , methyltransferase , chemistry , gel electrophoresis , sepharose , biochemistry , chromatography , methionine , amino acid , methylation , dna
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 (4×(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 5.0×10 −6 M for S ‐adenosyl‐ l ‐methionine and a V max of 205 pmol methyl ‐ 14 C transferred min −1 mg −1 protein.