Lipoprotein lipase from rainbow trout differs in several respects from the enzyme in mammals.
Lipoprotein lipase from rainbow trout differs in several respects from the enzyme in mammals.
复制标题
DOI：
10.1016/s0378-1119(02)00680-7
复制
发表时间：
2002-06
期刊：
影响因子：
3.5
通讯作者：
A. Lindberg;G. Olivecrona
中科院分区：
文献类型：
--
作者：
A. Lindberg;G. Olivecrona
以前，我们在虹鳟鱼的组织中发现了具有与脂蛋白脂肪酶（LPL）相似特征的脂肪酶活性[Biochim. Biophys. Acta 1255（1995）205]，而没有发现与相关肝脂酶的等价物，还鉴定和表征了载脂蛋白CII的等价物[Gene 254（2000）189]。我们在这里提出了完整的核苷酸序列LPL从虹鳟鱼（Oncorhynchusmykiss），并研究了酶的一些特性。与在哺乳动物中发现的相反，LPL mRNA在成年鳟鱼的肝脏中表达。这表明鳟鱼LPL执行肝脂肪酶已经进化到在哺乳动物中接管的功能。与牛和人LPL相比，鳟鱼LPL在37 °C下不稳定。可能与不稳定性相关的两个序列差异是鳟鱼LPL在C-末端结构域中缺乏二硫键并且缺乏Pro 258。该残基在来自所有哺乳动物的LPL中是保守的，并且已显示对于酶在37° C下的稳定性至关重要。在肝素-琼脂糖凝胶层析上，鳟鱼和鸡LPL在比牛（或其他哺乳动物）LPL更高的盐浓度下洗脱。LPL的C-末端暗示了肝素结合，鳟鱼和鸡酶的较高肝素亲和力可能是因为它们在C-末端具有17和15个额外的氨基酸残基，其中3个残基带正电荷。
Previously we found lipase activity with characteristics similar to lipoprotein lipase (LPL) in tissues from rainbow trout [Biochim. Biophys. Acta 1255 (1995) 205], whereas no equivalent to the related hepatic lipase could be found. An equivalent to apolipoprotein CII was also identified and characterized [Gene 254 (2000) 189]. We present here the full nucleotide sequence for LPL from rainbow trout (Oncorhynchusmykiss) and have investigated some properties of the enzyme. In contrast to what has been found in mammals, LPL mRNA was expressed in livers of adult trout. This indicates that trout LPL carries out functions that hepatic lipase has evolved to take over in mammals. Trout LPL was unstable at 37 °C compared with bovine and human LPL. Two sequence differences that may relate to the instability are that trout LPL lacks the disulfide bridge in the C-terminal domain and lacks Pro258. This residue is conserved in LPL from all mammals and has been shown to be critical for enzyme stability at 37° C. On chromatography on heparin–Sepharose trout and chicken LPL eluted at higher salt concentration than bovine (or other mammalian) LPL. The C-terminal end of LPL has been implied in heparin binding and the higher heparin affinity of the trout and chicken enzymes may be because they have 17 and 15 extra amino acid residues at the C-terminal end, of which three residues are positively charged.