中文摘要：

为研究杜氏盐藻碳酸酐酶的两个结构域的耐盐性，将杜氏盐藻碳酸酐酶的两个串联结构域分别表达与纯化，利用酶学方法和光谱学方法分别研究这两个结构域各自的活性及其对盐的耐受性．研究发现，N端结构域不具有催化活性，仅有C端结构域具有活性，而且其活性随着盐浓度的增加而增加，这同杜氏盐藻碳酸酐酶在广泛的盐浓度内的活性变化趋势一致．光谱学方法发现，随着盐浓度的增加，C端结构域的二级结构和三级结构并不发生显著变化，活性中心结构逐渐松弛，从而增加了C端结构域活性中心的活力，提高了盐藻碳酸酐酶的活性．

英文摘要：

In order to study the salt-tolerance of the two domains of internal duplicated carbonic anhydrase of Dunaliella salina, the two tandem repeats are expressed and purified respectively via using both enzymatic and spectroscopy methods to assay their activities and salt-tolerance. Although enzymatic assays for N terminal domain did not reveal any catalytic activity, C terminal domain which resembles carbonic anhydrase of Dunaliella salina possessed enzymatic activity and responded to a wide range of salt concentration. Enzymatic activity of C terminal domain increased with increasing salinities. Spectroscopy method indicated that with the increase of salt concentration, significant changes were not found in secondarystructures and tertiary structures of C terminal domain, but structure of active site of C terminal domain relaxed gradually, thereby the vitality of the active site of C terminal domain increased and activity of carbonic anhydrase of Dunaliella salina was enhanced.