Keratinases have drawn increasing attention in recent decades owing to their catalytic versatility and broad applications from agriculture to medicine. In the present study, we isolated a highly keratinolytic and fibrinolytic bacterium from the campus soil and named it Stenotrophomonas sp. LMY based on genetic information. To identify the potential keratinase genes, the genome sequence of the strain was obtained and analyzed. Sequence alignment and comparison revealed that the protein 1_737 (KerZJ) had the highest sequence homology to a reported keratinase KerBL. We recombinantly expressed KerZJ in Escherichia coli Origami™ (DE) pLysS and purified it to homogeneity. KerZJ showed the highest activity at 40 °C and pH 9.0, and metal ions exhibited no significant effects on its activity. Although reducing agents would break the disulfide bonds in KerZJ and reduce its activity, KerZJ still exhibited the ability to hydrolyze feather keratin in the presence of β-ME. KerZJ could efficiently digest human prion proteins. In addition, KerZJ showed fibrinolytic activity on fibrin plates and effectively eliminated blood clots in a thrombosis mouse model without side effects. Our results suggest that KerZJ is a versatile keratinase with significant potential for keratin treatment, decontamination of prions, and fibrinolytic therapy.

近几十年来，角蛋白酶由于其催化多功能性和从农业到医学的广泛应用而引起了越来越多的关注。在本研究中，我们从校园土壤中分离出一种高度角蛋白溶解和纤维蛋白溶解的细菌，并将其命名为寡养单胞菌。基于遗传信息的 LMY。为了鉴定潜在的角蛋白酶基因，获得并分析了该菌株的基因组序列。序列比对和比较表明，蛋白质1_737（KerZJ）与已报道的角蛋白酶KerBL具有最高的序列同源性。我们在大肠杆菌Origami™ (DE) pLysS 中重组表达 KerZJ，并将其纯化至均质。 KerZJ在40℃和pH 9.0时表现出最高活性，金属离子对其活性没有显着影响。尽管还原剂会破坏KerZJ中的二硫键并降低其活性，但KerZJ在β-ME存在下仍然表现出水解羽毛角蛋白的能力。 KerZJ 可以有效消化人类朊病毒蛋白。此外，KerZJ 在纤维蛋白板上显示出纤溶活性，并能有效消除血栓小鼠模型中的血栓，且无副作用。我们的结果表明 KerZJ 是一种多功能角蛋白酶，在角蛋白治疗、朊病毒净化和纤溶治疗方面具有巨大潜力。