Insulin-induced lipid binding to hemoglobin

Autor: VESNA NIKETIC, DICK HOEKSTRA, KAREN KLAPPE, MILAN NIKOLIC, NENAD TOMASEVIC
Jazyk: angličtina
Rok vydání: 2003
Předmět:
Zdroj: Journal of the Serbian Chemical Society, Vol 68, Iss 1, Pp 25-33 (2003)
Druh dokumentu: article
ISSN: 0352-5139
Popis: Under hypoglycemic conditions, concomitant hyperinsulinism causes an apparent modification of hemoglobin (Hb) which is manifested by its aggregation (Niketi} et al., Clin. Chim. Acta 197 (1991) 47). In the present work the causes and mechanisms underlying this Hb modification were studied. Hemoglobin isolated from normal erythrocytes incubated with insulin was analyzed by applying 31P-spectrometry and lipid extraction and analysis. To study the dynamics of the plasma membrane during hyperinsulinism, a fluorescent lipid-analog was applied. In the presence of insulin, phosphatidylserine (PS), phosphatidylethanolamine (PE) and cholesterol were found to bind to Hb. Lipid binding resulted in Hb aggregation, a condition that can be reproduced when phospholipids are incubated with Hb in vitro. Using a fluorescent lipid-analog, it was also shown that exposing erythrocytes to supraphysiological concentrations of insulin in vitro resulted in the internalization of lipids. The results presented in this work may have relevance to cases of diabetes mellitus and hypoglycemia.
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