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Substrate Promiscuity of N-Acetylhexosamine 1-Kinases
Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616, USA
Departments of Biochemistry and Chemistry, Ohio State University, Columbus, OH 43210, USA
Current Address: National Glycoengineering Research Center, Shandong University, Jinan, Shandong 250012, China
Current Address: Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi, UP 221 005, India
* Author to whom correspondence should be addressed.
Received: 1 July 2011; in revised form: 22 July 2011 / Accepted: 25 July 2011 / Published: 28 July 2011
Abstract: N-Acetylhexosamine 1-kinase (NahK) catalyzes the direct addition of a phosphate from adenosine 5'-triphosphate (ATP) to the anomeric position of N-acetylhexosamine and shows similar activity towards N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc). Herein we report the cloning, characterization, and substrate specificity studies of two NahKs from Bifidobacterium infantis ATCC15697 and Bifidobacterium longum ATCC55813, respectively. A new capillary electrophoresis assay method has been developed for enzyme activity assays. Both enzymes have a good expression level in E. coli (180–185 mg/L culture) and can tolerate diverse modifications at C2 of GlcNAc and GalNAc. Various GlcNAc derivatives with C6, both C2 and C6, as well as both C2 and C3 modifications are tolerable substrates for the newly cloned NahKs. Quite interestingly, despite of their low activities toward glucose and galactose, the activities of both NahKs are much higher for mannose and some of its C2, C4, and C6 derivatives. These NahKs are excellent catalysts for enzymatic and chemoenzymatic synthesis of carbohydrates.
Keywords: N-acetylgalactosamine; N-acetylglucosamine; N-acetylhexosamine 1-kinase; mannose; substrate specificity
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Li, Y.; Yu, H.; Chen, Y.; Lau, K.; Cai, L.; Cao, H.; Tiwari, V.K.; Qu, J.; Thon, V.; Wang, P.G.; Chen, X. Substrate Promiscuity of N-Acetylhexosamine 1-Kinases. Molecules 2011, 16, 6396-6407.
Li Y, Yu H, Chen Y, Lau K, Cai L, Cao H, Tiwari VK, Qu J, Thon V, Wang PG, Chen X. Substrate Promiscuity of N-Acetylhexosamine 1-Kinases. Molecules. 2011; 16(8):6396-6407.
Li, Yanhong; Yu, Hai; Chen, Yi; Lau, Kam; Cai, Li; Cao, Hongzhi; Tiwari, Vinod Kumar; Qu, Jingyao; Thon, Vireak; Wang, Peng George; Chen, Xi. 2011. "Substrate Promiscuity of N-Acetylhexosamine 1-Kinases." Molecules 16, no. 8: 6396-6407.