海洋希瓦氏菌 UMI-18 的 PL-17 外切型海藻酸盐裂解酶产生新型二聚 4-脱氧-L-赤-5-己酮糖醛酸。

Production of a novel dimeric 4-deoxy-L-erythro-5-hexoseulose uronic acid by a PL-17 exolytic alginate lyase from Hydrogenophaga sp. UMI-18.

机构信息

Laboratory of Marine Biotechnology and Microbiology, Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-0821, Japan.

Instrumental Analysis Div, Global Facility Center, Creative Research Institution, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan.

出版信息

Biochem Biophys Res Commun. 2020 May 14;525(4):982-988. doi: 10.1016/j.bbrc.2020.03.029. Epub 2020 Mar 12.

DOI:10.1016/j.bbrc.2020.03.029

PMID:32171524

Abstract

Hydrogenopahaga sp. strain UMI-18 is an alginolytic bacterium that can produce poly(3-hydroxybutylate) (PHB) using alginate as its sole carbon source. Genome analysis indicated that this strain harbors both PHB-synthesizing and alginate-assimilating gene clusters. In the present study, we cloned HyAly-I gene that encodes a PL-17 exolytic alginate lyase and investigated its enzymatic properties using recombinant HyAly-I (recHyAly-I) that was produced by Escherichia coli. The recHyAly-I preferably depolymerized poly(β-D-mannuronate) block of alginate in an exolytic manner at an optimal temperature and a pH at 40 °C and pH 6.0, respectively. It released 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEH) from the non-reducing terminus of polymer and oligomer substrates. Interestingly, recHyAly-I was found to produce a novel unsaturated disaccharide, i.e., dimeric DEH (diDEH), along with monomeric DEH. Production of diDEH was prominent in the degradation of trisaccharides.

摘要

氢噬菌属菌株 UMI-18 是一种能以褐藻胶为唯一碳源产生聚 3-羟基丁酸酯（PHB）的解聚菌。基因组分析表明，该菌株同时拥有 PHB 合成和褐藻胶同化基因簇。本研究克隆了编码 PL-17 外切型褐藻胶裂解酶的 HyAly-I 基因，并利用大肠杆菌生产的重组 HyAly-I（recHyAly-I）研究了其酶学性质。recHyAly-I 优先以外切方式在 40°C 和 pH6.0 下分解褐藻胶的聚-β-D-甘露糖酸盐块。它从聚合物和低聚物底物的非还原末端释放 4-脱氧-L-赤-5-己酮糖醛酸（DEH）。有趣的是，recHyAly-I 被发现能产生一种新型不饱和二糖，即二聚 DEH（diDEH），以及单体 DEH。二聚 DEH 的产生在三糖的降解中尤为明显。