Ghrelin Interacts with Human Plasma Lipoproteins
| Autor: | Yvon Carpentier, Christine Delporte, Mirjam Hacquebard, Françoise Grégoire, Carine De Vriese |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Adult
Male medicine.medical_specialty Acylation Lipoproteins Peptide Hormones Lipoproteins VLDL Peptide hormone Chromatography Affinity Carboxylesterase Endocrinology Internal medicine medicine Humans Enzyme Inhibitors Platelet Activating Factor Triglycerides Butyrylcholinesterase chemistry.chemical_classification Stomach digestive oral and skin physiology Ghrelin Growth hormone secretion Protein Structure Tertiary Lipoproteins LDL medicine.anatomical_structure Enzyme chemistry 1-Alkyl-2-acetylglycerophosphocholine Esterase Female lipids (amino acids peptides and proteins) Caprylates Lipoproteins HDL hormones hormone substitutes and hormone antagonists Lipoprotein |
| Zdroj: | Endocrinology. 148:2355-2362 |
| ISSN: | 1945-7170 0013-7227 |
| DOI: | 10.1210/en.2006-1281 |
| Popis: | Ghrelin, a peptide hormone produced predominantly by the stomach, stimulates food intake and GH secretion. The Ser3 residue of ghrelin is mainly modified by a n-octanoic acid. In the human bloodstream, ghrelin circulates in two forms: octanoylated and desacylated. We previously demonstrated that ghrelin is desoctanoylated in human serum by butyrylcholinesterase (EC 3.1.1.8) and other esterase(s), whereas in rat serum, only carboxylesterase (EC 3.1.1.1) is involved. The aims of this study were to determine the role of lipoprotein-associated enzymes in ghrelin desoctanoylation and the role of lipoproteins in the transport of circulating ghrelin. Our results show that ghrelin desoctanoylation mostly occurred in contact with low-density lipoproteins (LDLs) and lipoprotein-poor plasma subfractions. Butyrylcholinesterase and platelet-activating factor acetylhydrolase (EC 3.1.1.47) were responsible for the ghrelin hydrolytic activity of the lipoprotein-poor plasma and LDL subfractions, respectively. Moreover, we observed that ghrelin is associated with triglyceride-rich lipoproteins (TRLs), high-density lipoproteins (HDLs), very high-density lipoproteins (VHDLs), and to some extent LDLs. In conclusion, we report that the presence of the acyl group is necessary for ghrelin interaction with TRLs and LDLs but not HDLs and VHDLs. Ghrelin interacts via its N- and C-terminal parts with HDLs and VHDLs. This suggests that, whereas TRLs mostly transport acylated ghrelin, HDLs and VHDLs transport both ghrelin and des-acyl ghrelin. |
| Databáze: | OpenAIRE |
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