研究者情報 | 神奈川大学

イブカ　アキコ Ibuka Akiko 井深　章子所属神奈川大学化学生命学部生命機能学科神奈川大学大学院理学研究科理学専攻（生物科学領域）職種教授
言語種別	英語
発行・発表の年月	2011/01
形態種別	学術雑誌
査読	査読あり
標題	Roles of Residues Cys69, Asn104, Phe160, Gly232, Ser237, and Asp240 in Extended-Spectrum beta-Lactamase Toho-1
執筆形態	共著
掲載誌名	ANTIMICROBIAL AGENTS AND CHEMOTHERAPY
掲載区分	国外
出版社・発行元	AMER SOC MICROBIOLOGY
巻・号・頁	55(1),pp.284-290
著者・共著者	Akiko Shimizu-Ibuka, Mika Oishi, Shoko Yamada, Yoshikazu Ishii, Kiyoshi Mura, Hiroshi Sakai, Hiroshi Matsuzawa
概要	Toho-1 is an extended-spectrum class A beta-lactamase that has high activity toward cefotaxime. In this study, we investigated the roles of six residues suggested to be critical for the substrate specificity expansion of Toho-1 in previous structural analyses. The mutants were analyzed both for their kinetic properties and their effect on drug susceptibilities. The results indicate that the substitutions of Asn104 and Ser237 have certain effects on expansion of substrate specificity, while those of Cys69 and Phe160 have less effect, and that of Asp240 has no effect on the hydrolysis of any substrates. Gly232, which had been assumed to increase the flexibility of the substrate binding site, was revealed not to be critical for the expansion of substrate specificity of this enzyme, although this substitution resulted in deleterious effects on expression and stability of the enzyme.
DOI	10.1128/AAC.00098-10
ISSN	00664804