中文摘要：

胸苷激酶（thymidine kinase，TK）是嘧啶核苷酸补救合成途径的重要酶之一，包括两个亚家族：1型TK及2型TK。这两种TK的作用机理相同，都可以将脱氧胸苷磷酸化为脱氧胸苷-磷酸，但两者的蛋白结构及催化底物范围有较大差异。两种TK都与人类及动物的各种疾病，如心肌病、肿瘤等密切相关，它们还影响寄生虫的毒性、生长及繁殖等。

英文摘要：

Thymidine kinase is one of important enzymes involved in the DNA-salvage pathway, including type 1 and type 2 subfamilies. Both the two kinds of TK can phosphorylate deoxythymidine to deoxythymidine monophosphate through the same mechanism. However, the protein structure and catalytic substrates of them are different. Research has shown that both the two kinds of TK are associated with human and animal diseases, such as cardiomyopathy, tumor, etc. In addition, TK is also involved in the toxicity, growth and reproduction of parasltes.