摘要
蛋氨酸是唯一1种含硫必需氨基酸,是蛋白合成和细胞转甲基化作用的必需成分,同时也是同型半胱氨酸的前体物质.研究发现,与正常细胞相比,肿瘤细胞对蛋氨酸呈现出依赖的特性.这种依赖是一种代谢缺陷,可从蛋氨酸的生物代谢角度解释肿瘤细胞产生蛋氨酸依赖的缺陷.正常细胞代谢中存在蛋氨酸补救途径即5,-甲硫基腺苷酸(MTA)循环合成蛋氨酸,而肿瘤细胞却无此途径,表现出对蛋氨酸的绝对需要.L-蛋氨酸γ-裂解酶能够特异性地裂解L-蛋氨酸产生氨、α-丁酮酸和甲硫醇.蛋氨酸酶在抗肿瘤研究中表现出对肿瘤特异性高,毒副作用小等特点,有较好的发展前景,给肿瘤基因治疗开辟了新的路径.
Methionine is the only essential sulfur-containing amino acid that is needed for the synthesis of protein and transmethylation. And it is the precursor of homocysteine. Comparing with normal cells, some cancer cells exhibited methionine dependence. It is a kind of metabolic defect which can be explained by biological mechanism of methionine. Methionine salvage pathway, also called the 5＇-methylthioadenosine （MTA） cycle was a universal pathway in normal cells while cancer cells have absolute requirement for methionine. The L-methionine c~ -deamino- ＂y -mercaptomethane-lyase （methioninase） can degrade methionine into ammonia, et -ketobutyrate and methanthiol. Methioninase have the advantage of high specificity to cancer cells with few side effects which shows a bright development prospect in the gene therapy for tumor.
出处
《昆明医科大学学报》
CAS
2013年第6期144-148,共5页
Journal of Kunming Medical University
基金
国家自然科学基金资助项目(30760287)
云南省科技计划基金资助项目(2009CC022)
关键词
蛋氨酸
蛋氨酸依赖
蛋氨酸代谢
蛋氨酸酶
肿瘤治疗
Methionine
Methionine dependence
Methionine salvage pathway
Methioninase
Tumor therapy
