本研究以马鲛鱼贮藏期内腐败产胺菌-霍氏肠杆菌（Enterobacter hormaechei）为研究对象，通过基因工程和生物信息学多种分析方法，探究马鲛鱼种霍氏肠杆菌精氨酸脱羧酶的理化性质。通过T-A克隆并测序得到ADC基因，将其翻译成蛋白序列，然后预测蛋白质一级结构、二级结构以及三维构象，分析ADC蛋白质的理化性质及其功能。结果显示：ADC蛋白由93个氨基酸构成，预估分子量大小约为10.82 ku、理论等电点是8.64、原子组成为C492H746N136O135S 3、半衰期>10 h（大肠杆菌，体内）、脂肪系数是86.02；总平均亲水性是-0.35整体表现为亲水性，是可溶性蛋白；不稳定系数为48.57，且ADC蛋白不存在信号肽，不是分泌蛋白。这些结果以及同时预测的ADC蛋白的二级结构和三维构象，为后续的深入研究提供参考，今后在基因克隆的基础上，将进行蛋白质的表达、分离纯化和性质研究，进一步解析精氨酸脱羧酶。

In this study, Enterobacter hormaechei, a spoilage amine-producing bacteria during storage of mackerel, was used as the research object. The physico-chemical properties of arginine decarboxylase of Enterobacter hormaechei in Scomberomorus niphonius were examined by various of genetic engineering and bioinformatic methods. The ADC gene was cloned and sequenced by T-A, translated into a protein sequence, before the primary structure, secondary structure and three-dimensional conformation of the protein were predicted, and the physico-chemical properties and functions of the ADC protein were analyzed. The results showed that the ADC protein was composed of 93 amino acids, with the estimated molecular weight roughly as 10.82 ku, the theoretical isoelectric point as 8.64, the atomic composition as C492 H746 N136 O135 S3, and the half-life >10 h (E. coli, in vivo), and the fat coefficient as 86.02. With the total average hydrophilicity as -0.35, the overall performance of the protein was hydrophilic. Behaving like a soluble protein with the instability coefficient as 48.57, the ADC protein did not have a signal peptide and was a secreted protein. These results as well as the simultaneously predicted secondary structure and three-dimensional conformation of the ADC protein provide a reference for subsequent in-depth research. In the future, on the basis of gene cloning, protein expression, separation and purification and properties research should be carried out to analyze further arginine decarboxylase.

辽宁省自然科学基金项目（20180551123）