Human hepatic lipase. Cloned cDNA sequence, restriction fragment length polymorphisms, chromosomal localization, and evolutionary relationships with lipoprotein lipase and pancreatic lipase.
Human hepatic lipase. Cloned cDNA sequence, restriction fragment length polymorphisms, chromosomal localization, and evolutionary relationships with lipoprotein lipase and pancreatic lipase.
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DOI：
10.1016/s0021-9258(19)57271-4
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发表时间：
1988-01
期刊：
影响因子：
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通讯作者：
S. Datta;C. Luo;Wen-Hsiung Li;P. Vantuinen;D. Ledbetter;Myles Brown;San‐Hwan Chen;Shyan-Woei Liu;L. Chan
中科院分区：
文献类型：
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作者：
S. Datta;C. Luo;Wen-Hsiung Li;P. Vantuinen;D. Ledbetter;Myles Brown;San‐Hwan Chen;Shyan-Woei Liu;L. Chan
人肝脂肪酶是高密度脂蛋白(HDL2)代谢的重要酶，参与HDL2向HDL3的转化。从人肝脏的两个lambda gt11文库中鉴定出三个人肝脂酶基因克隆。该序列预测了一个由476个氨基酸残基组成的蛋白质，其前面有一个23个残基的信号肽。确定了四个潜在的N-糖基化位点，其中两个在大鼠肝脂肪酶中保守。在与人、小鼠和牛脂蛋白脂酶的比对中，这两个相同的位置在所有三个物种的脂蛋白脂酶中也是保守的。半胱氨酸残基的严格保守也是显而易见的。氨基酸序列的比较分析表明，肝脂酶的进化速度很快，2.07×10(-9)个/位/年，大约是脂蛋白脂肪酶的4倍，是胰腺脂肪酶的一半。此外，肝脏脂肪酶和胰腺脂肪酶在进化上似乎比它们中的任何一个都更接近脂蛋白脂肪酶。Southern杂交分析显示，HindIII和MspI酶的肝脂酶基因存在高频限制性片段长度多态。这些多态性将有助于肝脂酶基因的单倍型和连锁分析。以克隆的人肝脂肪酶基因为杂交探针，对13个人-啮齿类体细胞杂交进行了Southern杂交分析。对不同杂交克隆的一致性分析表明，肝脂酶基因位于人类15号染色体的长臂上。对含有15号染色体不同易位的杂交种的分析表明，该基因定位在15q15-q22区域。
Human hepatic lipase is an important enzyme in high density lipoprotein (HDL) metabolism, being implicated in the conversion of HDL2 to HDL3. Three human hepatic lipase cDNA clones were identified in two lambda gt11 libraries from human liver. The cDNA-derived amino acid sequence predicts a protein of 476 amino acid residues, preceded by a 23-residue signal peptide. Four potential N-glycosylation sites are identified, two of which are conserved in rat hepatic lipase. On alignment with human, mouse, and bovine lipoprotein lipase, the same two sites were also conserved in lipoprotein lipase in all three species. Stringent conservation of the cysteine residues was also evident. Comparative analysis of amino acid sequences shows that hepatic lipase evolves at a rapid rate, 2.07 x 10(-9) substitutions/site/year, about four times that in lipoprotein lipase and half that in pancreatic lipase. Further, hepatic lipase and pancreatic lipase appear to be evolutionarily closer to each other than either of them is to lipoprotein lipase. Southern blot analysis revealed high frequency restriction fragment length polymorphisms of the hepatic lipase gene for the enzymes HindIII and MspI. these polymorphisms will be useful for haplotype and linkage analysis of the hepatic lipase gene. Using cloned human hepatic lipase cDNA as a hybridization probe, we performed Southern blot analysis of a panel of 13 human-rodent somatic cell hybrids. Concordance analysis of the various hybrid clones indicates that the hepatic lipase gene is located on the long arm of human chromosome 15. Analysis of hybrids containing different translocations of chromosome 15 localized the gene to the region 15q15—-q22.