Influence of Acylation of a Peptide Corresponding to the Amino-Terminal Region of Endothelial Nitric Oxide Synthase on the Interaction with Model Membranes
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- 作者：Belé ; n Yé ; lamos ; Fernando Roncal ; Juan P. Albar ; Ignacio Rodrí ; guez-Crespo ; and Francisco Gavilanes
- 刊名：Biochemistry
- 出版年：2006
- 出版时间：January 31, 2006
- 年：2006
- 卷：45
- 期：4
- 页码：1263 - 1270
- 全文大小：114K
- 年卷期：v.45,no.4(January 31, 2006)
- ISSN：1520-4995
文摘
Covalent attachment of fatty acids to proteins is a common form of protein modification whichhas been shown to influence both structure and interaction with membranes. Endothelial nitric oxidesynthase (eNOS) is dually acylated by the fatty acids myristate and palmitate. We have synthesized fourpeptides corresponding to the first 28 amino acids of the N-terminal region of eNOS. Besides thenonacylated eNOS sequence, three additional peptides with different degrees of acylation have beenobtained: myristoylated, doubly palmitoylated, and dually myristoylated and doubly palmitoylated.Acylation itself, myristic and/or palmitic, confers the peptide the ability to adopt extended conformations,indicated by the fact that the CD spectrum of all acylated peptides has a minimum at ~215 nm characteristicof 
-sheet structure. The nonacylated sequence interacts with model membranes composed of acidicphospholipids probably through ionic interactions with the polar headgroup of the phospholipids. However,the acylated peptides are able to insert deeply into the hydrophobic core of both neutral and acidicphospholipids, maintaining the spectral features of extended conformations. When DMPC vesiclescontaining cholesterol and sphingomyelin at 10% were used, the insertion of the triacylated peptide almostcompletely canceled the thermal transition, although the interaction of the other acylated peptides alsoreduced the transition amplitude but to a much lower extent and affected only the acyl chains in the fluidstate.
-sheet structure. The nonacylated sequence interacts with model membranes composed of acidicphospholipids probably through ionic interactions with the polar headgroup of the phospholipids. However,the acylated peptides are able to insert deeply into the hydrophobic core of both neutral and acidicphospholipids, maintaining the spectral features of extended conformations. When DMPC vesiclescontaining cholesterol and sphingomyelin at 10% were used, the insertion of the triacylated peptide almostcompletely canceled the thermal transition, although the interaction of the other acylated peptides alsoreduced the transition amplitude but to a much lower extent and affected only the acyl chains in the fluidstate.