title: Purification and characterization of chromium-binding substances from high-chromium yeast.
abstract: As a highly efficient and easily absorbable source of chromium, the identities of the chromium-binding substances in yeast remain unclear. In this study, a mild extraction procedure involving extraction with ammonia, three-gel filtration, and high-performance liquid chromatography was adopted to obtain two chromium-binding substances from high-chromium yeast. A low-molecular-weight chromium-binding substance was identified, with mass-to-charge ratios (m/z) of 769 and 712, which included glutamic acid, glycine, and cysteine in an approximate ratio of 1:1:1, as well as nicotinic acid and chromium(III). Furthermore, it significantly potentiated (by 51%) the action of insulin to stimulate the conversion of (14)C-glucose into lipid in adipocytes. A novel high-molecular-weight chromium-binding substance was also isolated: electrospray ionization tandem mass spectrometry tentatively identified it as HUB1 target protein-1, glyceraldehyde-3-phosphate dehydrogenase, or ribosomal protein L2A(L5A)(rp8)(YL6). This is the first report of a high-molecular-weight chromium-binding substance in yeast and merits further studies.
authors: Key Laboratory of Agro-Food Processing and Quality Control, Ministry of Agriculture, Beijing 100193, PR China.
authors: Lu
authors: L
authors: Liu
authors: Jia-ping
authors: JP
authors: Lv
authors: Hankie
authors: H
authors: Uluko
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D002857:Chromium / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D012441:Saccharomyces cerevisiae / Q000737:chemistry* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002352:Carrier Proteins; D029701:Saccharomyces cerevisiae Proteins; D002857:Chromium