Vanadates form insoluble complexes with histones.
Vanadium oxoanions are known to have a variety of physiological effects including insulin-like activity, inhibition of phosphotyrosine phosphatases, as well as direct interactions with a variety of cellular proteins, such as microtubules. In this study, vanadate was found to form insoluble complexes with histones, as well as other positively charged proteins, in a concentration dependent fashion. This interaction occurred over a 0.5-10 mM range which corresponds to the concentration range required for many of vanadate's known physiological effects. Results from precipitation experiments using vanadate solutions with or without the yellow-orange decavanadate indicated that the decamer form is primarily responsible for this precipitation. Vanadate was able to selectively precipitate histones from soluble chromatin as well as from a soluble bacterial protein extract to which a low concentration of histones had been added. Vanadate was also able to effectively precipitate histone from solutions as low as 0.006 mg/mL histone. Thus, the selective precipitation of histones and other positively charged proteins by vanadate can be utilized as a tool for protein purification. In addition, this interaction may provide insight into the mechanisms for the physiological effects of vanadate.
Michele
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DE
Department of Chemistry and Biochemistry, Calvin College, Grand Rapids, MI 49546, USA.
Thomsen
D
D
Louters
L L
LL
D000818:Animals; D002417:Cattle; D011232:Chemical Precipitation; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D012995:Solubility / Q000187:drug effects; D012996:Solutions; D014638:Vanadates / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology
D002843:Chromatin; D006657:Histones; D012996:Solutions; D014638:Vanadates