{"title":"Purification and characterization of agarases from a marine bacterium, Vibrio sp. PO-303.","authors":"Araki, Hayakawa, Lu, Karita, Morishita","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>A marine bacterium, Vibrio sp. PO-303, produced three kinds of extracellular agarases. These enzymes were purified to homogeneity by ammonium sulfate precipitation and successive column chromatographies. The molecular masses of agarase-a, -b, and -c were estimated to be 87.5, 115, and 57 kDa by SDS-PAGE with isoelectric point of 6.6, 3.4, and 8.4, respectively. These enzymes had maximal activity at pH 6.5-7.5 and at around 38-55 degreesC. They differed in their sequences at the amino termini of the protein chains. All enzymes were inhibited completely by Hg2+. Ag+, Cu2+, and Zn2+ strongly inhibited agarase-a and -c compared with agarase-b, and the activity of agarase-c fell wide by Al3+, Fe3+, and EDTA. Agarase-a hydrolyzed agarose to give neoagarotetraose and -hexaose as predominant products, but could not cleave neoagarotetraose. The main hydrolysis products of agarase-b were neoagarobiose from agarose and neoagarooligosaccharides more than dimer. Agarase-c could not cleave neoagarohexaose.</p>","PeriodicalId":79672,"journal":{"name":"Journal of marine biotechnology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1998-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of marine biotechnology","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
A marine bacterium, Vibrio sp. PO-303, produced three kinds of extracellular agarases. These enzymes were purified to homogeneity by ammonium sulfate precipitation and successive column chromatographies. The molecular masses of agarase-a, -b, and -c were estimated to be 87.5, 115, and 57 kDa by SDS-PAGE with isoelectric point of 6.6, 3.4, and 8.4, respectively. These enzymes had maximal activity at pH 6.5-7.5 and at around 38-55 degreesC. They differed in their sequences at the amino termini of the protein chains. All enzymes were inhibited completely by Hg2+. Ag+, Cu2+, and Zn2+ strongly inhibited agarase-a and -c compared with agarase-b, and the activity of agarase-c fell wide by Al3+, Fe3+, and EDTA. Agarase-a hydrolyzed agarose to give neoagarotetraose and -hexaose as predominant products, but could not cleave neoagarotetraose. The main hydrolysis products of agarase-b were neoagarobiose from agarose and neoagarooligosaccharides more than dimer. Agarase-c could not cleave neoagarohexaose.