D. R. Chhetri, S. Yonzone, Sanjeeta Tamang, A. Mukherjee
{"title":"L-myo-InositoL-1- phosphate synthase from bryophytes: purification and characterization of the enzyme from Lunularia cruciata (L.) Dum","authors":"D. R. Chhetri, S. Yonzone, Sanjeeta Tamang, A. Mukherjee","doi":"10.1590/S1677-04202009000300008","DOIUrl":null,"url":null,"abstract":"L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) catalyzes the conversion of D-glucose-6-phosphate to 1L-myo-inositol-1-phosphate, the rate limiting step in the biosynthesis of all inositol containing compounds. Myo-inositol and its derivatives are implicated in membrane biogenesis, cell signaling, salinity stress tolerance and a number of other metabolic reactions in different organisms. This enzyme has been reported from a number of bacteria, fungi, plants and animals. In the present study some bryophytes available in the Eastern Himalaya have been screened for free myo-inositol content. It is seen that Bryum corinatum, a bryopsid shows the highest content of free myo-inositol among the species screened. Subsequently , the enzyme MIPS has been partially purified to the tune of about 70 fold with approximately 18% recovery form the reproductive part bearing gametophytes of Lunularia cruciata. The L. cruciata synthase specifically utilized D-glucose-6-phosphate and NAD+ as its substrate and co-factor respectively. The optimum pH shown was 7.0 while the temperature maximum was at 30oC. The enzyme activity was slightly stimulated by Mg2+ and Ca2+; remarkably stimulated by NH4+; slightly inhibited by Mn2+; highly inhibited by Cu2+, Zn2+ and Hg2+. The Km values for D-glucose-6-phosphate and NAD+ was found to be 0.80 and 0. 034 mM respectively while the Vmax values were 2.8 and 1.21 mM for D-glucose-6-phosphate and NAD+ respectively.","PeriodicalId":9278,"journal":{"name":"Brazilian Journal of Plant Physiology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2009-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Brazilian Journal of Plant Physiology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1590/S1677-04202009000300008","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) catalyzes the conversion of D-glucose-6-phosphate to 1L-myo-inositol-1-phosphate, the rate limiting step in the biosynthesis of all inositol containing compounds. Myo-inositol and its derivatives are implicated in membrane biogenesis, cell signaling, salinity stress tolerance and a number of other metabolic reactions in different organisms. This enzyme has been reported from a number of bacteria, fungi, plants and animals. In the present study some bryophytes available in the Eastern Himalaya have been screened for free myo-inositol content. It is seen that Bryum corinatum, a bryopsid shows the highest content of free myo-inositol among the species screened. Subsequently , the enzyme MIPS has been partially purified to the tune of about 70 fold with approximately 18% recovery form the reproductive part bearing gametophytes of Lunularia cruciata. The L. cruciata synthase specifically utilized D-glucose-6-phosphate and NAD+ as its substrate and co-factor respectively. The optimum pH shown was 7.0 while the temperature maximum was at 30oC. The enzyme activity was slightly stimulated by Mg2+ and Ca2+; remarkably stimulated by NH4+; slightly inhibited by Mn2+; highly inhibited by Cu2+, Zn2+ and Hg2+. The Km values for D-glucose-6-phosphate and NAD+ was found to be 0.80 and 0. 034 mM respectively while the Vmax values were 2.8 and 1.21 mM for D-glucose-6-phosphate and NAD+ respectively.