Korant B D
Central Research Department, DuPont Experimental Station, Wilmington, Delaware.
Crit Rev Biotechnol. 1988;8(2):149-57. doi: 10.3109/07388558809150543.
Only a few viral diseases are presently treatable because of our limited knowledge of specific viral target molecules. An attractive class of viral molecules toward which chemotherapeutic agents could be aimed are proteases coded by some virus groups such as retro- or picornaviruses (poliomyelitis, common cold virus). The picornavirus enzymes were discovered first, and they have now been characterized by a combination of molecular-genetic and biochemical approaches. Several laboratories have expressed the picornaviral enzymes in heterologous systems and have reported proteolytic activity, as well as the high cleavage fidelity diagnostic of the viral proteases. After dealing with several technical difficulties often encountered in standard genetic engineering approaches, one viral protease is now available to us in quantity and is amendable to mutagenic procedures. The initial outcome of the mutagenesis studies has been the confirmation of our earlier work with inhibitors, which suggested a cysteine active-site class. There is a clustering of active-site residues which may be unique to these viruses. The requirement for an active-site cysteine-histidine pair in combination with detailed information on the viral cleavage sites has permitted design of selective inhibitors with attractive antiviral properties. Future goals include investigation of the structural basis for selective processing and application of the cleavage specificity to general problems in genetic engineering.
由于我们对特定病毒靶分子的了解有限，目前只有少数病毒性疾病可以得到治疗。一类有吸引力的可作为化学治疗药物作用靶点的病毒分子是某些病毒组编码的蛋白酶，如逆转录病毒或小核糖核酸病毒（脊髓灰质炎病毒、普通感冒病毒）。小核糖核酸病毒酶最早被发现，现在已通过分子遗传学和生物化学方法的结合进行了表征。几个实验室已在异源系统中表达了小核糖核酸病毒酶，并报告了其蛋白水解活性以及病毒蛋白酶特有的高切割保真度。在解决了标准基因工程方法中经常遇到的几个技术难题后，现在我们可以大量获得一种病毒蛋白酶，并且它适合进行诱变程序。诱变研究的初步结果证实了我们早期使用抑制剂的工作，这表明其活性位点属于半胱氨酸类。活性位点残基存在聚集现象，这可能是这些病毒所特有的。对活性位点半胱氨酸 - 组氨酸对的需求，结合有关病毒切割位点的详细信息，使得设计具有诱人抗病毒特性的选择性抑制剂成为可能。未来的目标包括研究选择性加工的结构基础，以及将切割特异性应用于基因工程中的一般问题。
