tailieunhanh - Báo cáo khoa học: The maltodextrin transport system and metabolism in Lactobacillus acidophilus NCFM and production of novel a-glucosides through reverse phosphorolysis by maltose phosphorylase

A gene cluster involved in maltodextrin transport and metabolism was identified in the genome of Lactobacillus acidophilus NCFM, which encoded a maltodextrin-binding protein, three maltodextrin ATP-binding cassette transporters and five glycosidases, all under the control of a tran-scriptional regulator of the LacI-GalR family. | ỊFEBS Journal The maltodextrin transport system and metabolism in Lactobacillus acidophilus NCFM and production of novel a-glucosides through reverse phosphorolysis by maltose phosphorylase Hiroyuki Nakai1 Martin J. Baumann1 Bent O. Petersen2 Yvonne Westphal3 Henk Schols3 Adiphol Dilokpimol1 Maher A. Hachem1 Sampo J. Lahtinen4 Jens 0. Duus2 and Birte Svensson1 1 Enzyme and Protein Chemistry Department of Systems Biology TechnicalUniversity of Denmark Kgs. Lyngby Denmark 2 Carlsberg Laboratory Valby Denmark 3 Laboratory of Food Chemistry Wageningen University The Netherlands 4 Danisco Health Nutrition Kantvik Finland Keywords glycoside hydrolase family 65 maltodextrin gene cluster reverse phosphorolysis a-glucosides p-glucose 1-phosphate Correspondence B. Svensson Enzyme and Protein Chemistry Department of Systems Biology TechnicalUniversity of Denmark Soltofts Plads Building 224 DK-2800 Kgs. Lyngby Denmark Fax 45 4588 6307 Tel 45 4525 2740 E-mail bis@ Received 12 August 2009 revised 9 October 2009 accepted 16 October 2009 doi A gene cluster involved in maltodextrin transport and metabolism was identified in the genome of Lactobacillus acidophilus NCFM which encoded a maltodextrin-binding protein three maltodextrin ATP-binding cassette transporters and five glycosidases all under the control of a transcriptional regulator of the LacI-GalR family. Enzymatic properties are described for recombinant maltose phosphorylase MalP of glycoside hydrolase family 65 GH65 which is encoded by malP GenBank of this gene cluster and produced in Escherichia coli. MalP catalyses phosphorolysis of maltose with inversion of the anomeric configuration releasing b-glucose 1-phosphate b-Glc 1-P and glucose. The broad specificity of the aglycone binding site was demonstrated by products formed in reverse phosphorolysis using various carbohydrate acceptor substrates and b-Glc 1-P as the donor. MalP showed strong preference for .