Yamamoto A, Wada O, Ono T
Eur J Biochem. 1987 Jun 15;165(3):627-31. doi: 10.1111/j.1432-1033.1987.tb11486.x.
A low-molecular-mass chromium-binding substance (LMCr), which is recognized as a detoxification ligand of chromium, was isolated from the livers of rabbits injected intravenously with K2Cr2O7 (200 mumol Cr/kg body wt) as a biologically active form. LMCr appears as an anionic, organic Cr compound with a relative molecular mass of 1500. It is composed of glutamic acid or glutamine, glycine, cysteine and aspartic acid or asparagine with a Cr/amino-terminal residue ratio of 4:1. The purified LMCr (10-300 ng Cr/ml) shows in vitro activities comparable to those of glucose tolerance factor in relation to insulin action. In the presence of insulin it enhances [U-14C]glucose conversion to 14CO (23-30% up) in rat epididymal adipocytes above the value obtained with insulin alone. LMCr also stimulates the rate of [3-3H]glucose incorporation into lipid by 30-40% with insulin or by 15-23% without insulin, as compared with the basic value obtained with insulin alone or without insulin. These findings suggest that LMCr plays essential roles in both glucose metabolism and detoxification of invaded Cr in the body.
一种低分子量铬结合物质（LMCr），被认为是铬的解毒配体，它是从静脉注射重铬酸钾（200微摩尔铬/千克体重）的兔子肝脏中分离出来的一种生物活性形式。LMCr表现为一种阴离子有机铬化合物，相对分子质量为1500。它由谷氨酸或谷氨酰胺、甘氨酸、半胱氨酸和天冬氨酸或天冬酰胺组成，铬与氨基末端残基的比例为4:1。纯化的LMCr（10 - 300纳克铬/毫升）在体外表现出与葡萄糖耐量因子在胰岛素作用方面相当的活性。在有胰岛素存在的情况下，它能增强大鼠附睾脂肪细胞中[U - 14C]葡萄糖转化为14CO2的能力（比单独使用胰岛素时提高23 - 30%）。与单独使用胰岛素或不使用胰岛素时的基础值相比，LMCr还能使[3 - 3H]葡萄糖掺入脂质的速率在有胰岛素时提高30 - 40%，在无胰岛素时提高15 - 23%。这些发现表明，LMCr在体内葡萄糖代谢和侵入铬的解毒过程中都起着重要作用。
