特异腐质霉角质酶-锚定肽融合蛋白的特性及在处理再生纸胶黏物中的应用

随着森林木材资源的减少,废纸回收利用越来越受到人们的重视。然而,废纸回收利用过程中产生的胶黏物会对再生纸的生产造成严重影响。生物法控制胶黏物主要是通过酶断裂胶黏物组分之间的酯键,防止胶黏物的絮凝,具有高效、专一、无污染等优势。角质酶是一种丝氨酸酯酶,可降解胶黏物中的部分成分。相关研究表明,锚定肽tachystatin A2 (TA2)具有结合聚氨酯的能力。本研究选取特异性腐质霉Humicolainsolens来源的角质酶HiC,通过大引物全质粒扩增法成功构建了融合蛋白HiC-TA2,并研究了酶学性质以及对胶黏物模式底物聚丙烯酸乙酯(PEA)的降解效率。结果表明,HiC-TA2对PEA的降解效率是HiC的1.5倍,其PEA粒径减小值是HiC的6.8倍,产物乙醇的生成量是HiC的1.4倍。证明TA2有助于提高HiC对PEA的降解效率。本研究可为生物法控制再生纸生产过程中产生的胶黏物提供有益的参考。

Characterization of Humicola insolens cutinase-tachystatin A2 fusion protein and its application in treatment of recycled paper stickies

With the decrease of forest timber resources, the recycling of waste paper has received increasing attention. However, the stickies produced in the process of waste paper recycling may negatively affect the production of recycled paper. The biological decomposition of stickies, which has the advantages of high efficiency, high specificity and pollution-free, is achieved mainly through the enzymatic cleavage of the ester bond in the stickies components to prevent flocculation. Cutinase is a serine esterase that can degrade some components of the stickies. Previous research indicated that the anchor peptide tachystatin A2 (TA2) is able to bind polyurethane. In this study, the cutinase HiC derived from Humicola insolens was used to construct a fusion protein HiC-TA2 by megaprimer PCR of the whole plasmid (MEGAWHOP). The enzymatic properties and the degradation efficiency of the fusion protein on poly(ethyl acrylate) (PEA), a model substrate of stickies component, were determined. The results showed that the degradation efficiency, the size decrease of PEA particle, and the amount of ethanol produced by HiC-TA2 were 1.5 times, 6.8 times, and 1.4 times of that by HiC, respectively. These results demonstrated that TA2 improved the degradation efficiency of HiC on PEA. This study provides a useful reference for biological decomposition of stickies produced in the process of recycled paper production.