新方法可大批量生产人源明胶

科学家报告说，他们开发了一种大批量生产基于人的明胶的新方法，这可以替代为明胶类型的甜点、糖果等产品而每年生产的30万吨动物明胶的一部分。该研究发表在了美国化学会的《农业与食品化学期刊》（Journal of Agriculture and Food Chemistry）上。

Jinchun Chen及其同事解释说，基于动物的明胶大多数是用牛和猪的骨骼和皮肤制成的，它可能带来诸如“疯牛病”等传染病的风险，而且可能引起一些人的免疫系统的应答。基于动物的明胶还有其他缺点，例如，各批次的质量不一，这为制造商带来了困难。因此科学家一直在寻找替代方法，包括开发一种人重组明胶，可能用于药物胶囊和其他医学应用。

为了克服这些困难，这组科学家开发并证明了一种方法，他们把人类明胶基因插入到了一种酵母中，后者可以制造明胶且具有可控的特征。这组科研人员还在测试人-酵母明胶从而弄清楚它与其他明胶相比粘稠度和其他属性如何。Chen和他的同事提出，他们的方法可能扩大规模从而生产大量明胶供商业使用。

原文出处：

J. Agric. Food Chem.     DOI: 10.1021/jf200778r

New Strategy for Expression of Recombinant Hydroxylated Human-Derived Gelatin in Pichia pastoris KM71

Huiming Duan,Sirajo Umar,Runsong Xiong,Jinchun Chen,

Gelatin is a well-known biopolymer, and it has a long history of use mainly as a gelling agent in the food industry. This paper reports a new method for producing recombinant hydroxylated human-derived gelatin in Pichia pastoris KM71. Three independent expression cassettes encoding for specific length of gelatin, prolyl 4-hydroxylase (P4H, EC 1.14.11.2), α-subunit (αP4H), and protein-disulfide isomerase (PDI) were individually cloned in one expression vector, pPIC9K. The modified gelatin gene and two subunit genes of P4H were under the control of two different inducible promoters, namely, alcohol oxidase 1 promoter (PAOX1) and formaldehyde dehydrogenase 1 promoter (PFLD1), respectively. The results of sodium dodecylsulfate-polyacrylamide gel electrophoresis show that a recombinant gelatin was successfully expressed in P. pastoris KM71 by methanol induction. Liquid chromatography coupled with tandem mass spectrometry analysis indicates that the expressed gelatin was hydroxylated with approximately 66.7% of proline residues in the Y positions of Gly-X-Y triplets. The results of nuclear magnetic resonance spectroscopy of recombinant gelatin test show that the 1H and 13C spectra have many corresponding characteristic displacement peaks, and amino acids composition analysis shows that it contains hydroxyproline and its UV absorption is consistent with the characteristics of gelatin.