Apoprotein metabolism in human obesity.
Apoproteins are the proteins of lipoproteins. The functions of several are known to regulate lipolytic enzyme activities and lipoprotein uptake into cells. The effects of overweight were studied on the rates of production and removal of some of these proteins. The major structural protein, apo-B, increased in concentration with overweight, in the very-low-density lipoproteins (VLDL), due to diminished removal of VLDL particles rather than to overproduction. The turnover of the apo-C group of apoproteins was not affected by overweight. Thus, despite increased production of triglyceride with fatness, there was no concomitant increased formation of the main protein (B) of triglyceride-rich VLDL, nor in that of the major catabolic protein (apo-CII) that initiates triglyceride removal. High-density lipoprotein cholesterol falls in obesity; yet our studies of the metabolism of the major proteins of HDL (apo-AI and apo-AII), showed that the formation of these increased with overweight. Since a major function of apo-AI and of HDL is to transport cholesterol, the increased production of HDL particles (in terms of proteins), is consistent with the increased need to transport additional cholesterol which is a feature of obesity.
D053304:Apolipoprotein C-II; D001053:Apolipoproteins / Q000378:metabolism*; D001055:Apolipoproteins B; D001056:Apolipoproteins C; D001835:Body Weight; D006801:Humans; D008079:Lipoproteins, VLDL / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism
D053304:Apolipoprotein C-II; D001053:Apolipoproteins; D001055:Apolipoproteins B; D001056:Apolipoproteins C; D008079:Lipoproteins, VLDL; D014280:Triglycerides