权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Molecular species of fatty acid binding protein and their function in lipid metabolism

脂肪酸结合蛋白的分子种类及其在脂质代谢中的功能

基本信息

批准号：
60480132
负责人：
ONO Teruo
金额：
$ 3.78万
依托单位：
Niigata University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1987
项目状态：
已结题

项目摘要

1. Molecular species of FABP and their tissue distribution:FABPs purified from rat brain and heart cytosol are immunologically unrelated to L-FABP and no L-FABP is present in either rat brain or heart cytosol. Thus, the ex= pression of FABP molecular species seems to be tissue specific. immunohistochemical studies revealed that the distribution pattern of the positive hepatocytes was uniform throughout the acini in fetuses but periportal in abults. In the rat intestine, the expression of L-FABP was changed in the course of ipithelial cell differentiation.2. Properties of charge isoforms and the function of FABPs:The origin of charge isoforms of L-FABP was partly explained by the covalent modi= fication of cysteine at 69 and by the molecular species of bound fatty acid.There are no difference in oleic acid binding to L-FABP and H-FABP. Binding of oleoyl DoA to H-FABP was nonsaturable process, possibly explained by nonspecific association of oleoyl CoA aggregates with H-FABP. On the other hand, there was specific and saturable binding of oleoyl CoA to L-FABP involving a single binding site per mole.Acly CoA synthetase activity of cell particulates was increased by the addition of L-FABP but not H-FABP, when fatty acid was added as the mixed phosphatidylcholine lipo= somes. The preference of H-FABP to heart cell particulates and L-FABP to liver cell particulates was demonstrated when acyl CoA synthetase activity was assayed using fatty acid-FABP complex as substrate.3. Cell response:DG-kinase which is involved in cell response of arachidonate release was purified from pig brain cytosol. Immunological studies show that DG-kinase is present in the cytosol as well as microsomal and synaptosomal membranes of the brain. Immunostaining of-brain tissues demonstrated that neurons were positively stained whereas glial cells were not stained. Although the extent of enzyme phosphorylation was limited, the results show that DG-kinase can be a phosphoprotein.

1. FABP的分子种类及其组织分布：从大鼠脑和心脏胞质溶胶中纯化的FABP与L-FABP在免疫学上无关，并且在大鼠脑或心脏胞质溶胶中不存在L-FABP。因此，FABP分子种类的表达似乎是组织特异性的。免疫组化结果显示，阳性肝细胞在胎儿的腺泡内均匀分布，而在胚胎的门静脉周围分布。在大鼠小肠中，L-FABP的表达随着上皮细胞分化而发生变化.电荷异构体的性质和功能：L-FABP电荷异构体的来源部分是由69位半胱氨酸的共价修饰和结合脂肪酸的分子种类决定的，油酸与L-FABP和H-FABP的结合没有差异。油酰辅酶A与H-FABP的结合是不饱和的过程，这可能是由于油酰辅酶A聚集体与H-FABP的非特异性结合所致。另一方面，有特定的和饱和的结合的油酰CoA的L-FABP涉及一个单一的结合位点每摩尔。Acly CoA合成酶活性的细胞颗粒的添加L-FABP增加，但不是H-FABP，当脂肪酸作为混合磷脂酰胆碱脂质体添加。以脂肪酸-FABP复合物为底物测定酰基辅酶A合成酶活性时，H-FABP优先于心脏细胞颗粒，L-FABP优先于肝细胞颗粒.细胞反应：从猪脑胞质溶胶中纯化了参与花生四烯酸释放的细胞反应的DG-激酶。免疫学研究表明，DG-激酶存在于脑的细胞溶质以及微粒体和突触体膜中。脑组织的免疫组化染色显示神经元呈阳性染色，而胶质细胞未染色。虽然酶磷酸化的程度是有限的，但结果表明DG-激酶可以是磷蛋白。