Purification and properties of biologically active chromium complex from bovine colostrum.
A biologically active, low-molecular-weight, chromium-binding substance present in milk (M-LMCr) was isolated from bovine colostrum and purified more than 2000 times by means of ethanol precipitation and successive ion-exchange and Sephadex gel chromatographies. The purified M-LMCr appeared to be an anionic organic Cr compound with a molecular weight of 1500, as determined by gel permeation chromatography. It contained aspartic acid, glutamic acid, glycine and cysteine in a ratio of 5:4:2:1 and no detectable carbohydrate. Although we were unable to detect nicotinic acid, some ultraviolet-absorbing (lambda max 260 nm) chemical structure was shown to be a constituent. Purified M-LMCr stimulated the rates of both [U-14C]glucose oxidation and [3-3H]glucose conversion into lipid in rat epididymal adipocytes at Cr concentrations greater than 1.5 ng/mL in relation to insulin action. This substance appears to have properties similar to those of glucose tolerance factor in yeast and the low-molecular-weight, chromium-binding substance present in mammalian liver. The role of M-LMCr in Cr nutrition and detoxication is discussed.
Yamamoto
A
A
Department of Hygiene, Gunma University School of Medicine, Maebashi, Japan.
Wada
O
O
Suzuki
H
H
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002857:Chromium / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D003126:Colostrum / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000378:metabolism / Q000494:pharmacology; D050356:Lipid Metabolism; D008970:Molecular Weight; D009539:Nicotinic Acids / Q000378:metabolism; D010084:Oxidation-Reduction; D011247:Pregnancy
D000596:Amino Acids; D007328:Insulin; D009539:Nicotinic Acids; C015240:glucose tolerance factor; D002857:Chromium; D005947:Glucose