{"title":"Expression and biochemical characterization of a novel NAD<sup>+</sup>-dependent xylitol dehydrogenase from the plant endophytic fungus Trichoderma gamsii.","authors":"Shuping Fei, Wenxiu Hu, Jingwen Shu, Ruirui Zhao, Jiatong Zhao, Mengwei Jiang, Wenwen Wu, Chaoqun Lian, Wanggang Tang","doi":"10.1016/j.pep.2025.106687","DOIUrl":null,"url":null,"abstract":"<p><p>Xylitol dehydrogenase (XDH; EC 1.1.1.9), encoded by the XYL2 gene, is a key enzyme in the fungal xylose metabolic pathway. In this work, a putative XDH from the plant endophytic fungus Trichoderma gamsii (TgXDH) was hetero-expressed in Escherichia coli BL21(DE3), purified to the homogeneity, and biochemically characterized. Sequence analysis revealed that TgXDH is 363 amino acids long and belongs to the zinc-containing medium-chain alcohol dehydrogenase superfamily. The size-exclusion chromatography analysis and SDS-PAGE showed that the purified recombinant TgXDH had a native molecular mass of ∼155 kDa and was composed of four identical subunits of molecular mass of ∼39 kDa. The optimum temperature and pH of this enzyme were 25 °C and pH 9.5, respectively. Kinetic analysis showed that it is an NAD<sup>+</sup>-dependent enzyme that has a polyol substrate preference (based on k<sub>cat</sub>/K<sub>m</sub>) in the order xylitol > ribitol ≈ d-sorbitol. The K<sub>m</sub> values for NAD<sup>+</sup> with these three polyols ranged from 0.23 to 0.70 mM. Moreover, TgXDH showed high substrate affinities as compared to most of its homologs. The K<sub>m</sub> values for xylitol, ribitol, and d-sorbitol were 5.23 ± 0.68 mM, 8.01 ± 1.22 mM, and 12.34 ± 1.37 mM, respectively. Collectively, the results will contribute to understanding the biochemical properties of a novel XDH from the filamentous fungi and provide a promising XDH for industrial production of ethanol.</p>","PeriodicalId":20757,"journal":{"name":"Protein expression and purification","volume":" ","pages":"106687"},"PeriodicalIF":1.4000,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Protein expression and purification","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.pep.2025.106687","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMICAL RESEARCH METHODS","Score":null,"Total":0}
引用次数: 0
Abstract
Xylitol dehydrogenase (XDH; EC 1.1.1.9), encoded by the XYL2 gene, is a key enzyme in the fungal xylose metabolic pathway. In this work, a putative XDH from the plant endophytic fungus Trichoderma gamsii (TgXDH) was hetero-expressed in Escherichia coli BL21(DE3), purified to the homogeneity, and biochemically characterized. Sequence analysis revealed that TgXDH is 363 amino acids long and belongs to the zinc-containing medium-chain alcohol dehydrogenase superfamily. The size-exclusion chromatography analysis and SDS-PAGE showed that the purified recombinant TgXDH had a native molecular mass of ∼155 kDa and was composed of four identical subunits of molecular mass of ∼39 kDa. The optimum temperature and pH of this enzyme were 25 °C and pH 9.5, respectively. Kinetic analysis showed that it is an NAD+-dependent enzyme that has a polyol substrate preference (based on kcat/Km) in the order xylitol > ribitol ≈ d-sorbitol. The Km values for NAD+ with these three polyols ranged from 0.23 to 0.70 mM. Moreover, TgXDH showed high substrate affinities as compared to most of its homologs. The Km values for xylitol, ribitol, and d-sorbitol were 5.23 ± 0.68 mM, 8.01 ± 1.22 mM, and 12.34 ± 1.37 mM, respectively. Collectively, the results will contribute to understanding the biochemical properties of a novel XDH from the filamentous fungi and provide a promising XDH for industrial production of ethanol.
期刊介绍:
Protein Expression and Purification is an international journal providing a forum for the dissemination of new information on protein expression, extraction, purification, characterization, and/or applications using conventional biochemical and/or modern molecular biological approaches and methods, which are of broad interest to the field. The journal does not typically publish repetitive examples of protein expression and purification involving standard, well-established, methods. However, exceptions might include studies on important and/or difficult to express and/or purify proteins and/or studies that include extensive protein characterization, which provide new, previously unpublished information.