Stopar David, Spruijt Ruud B, Hemminga Marcus A
University of Ljubljana, Biotechnical Faculty, Slovenia.
Chem Phys Lipids. 2006 Jun;141(1-2):83-93. doi: 10.1016/j.chemphyslip.2006.02.023. Epub 2006 Mar 29.
Bacteriophage M13 major coat protein is extensively used as a biophysical, biochemical, and molecular biology reference system for studying membrane proteins. The protein has several elements that control its position and orientation in a lipid bilayer. The N-terminus is dominated by the presence of negatively charged amino acid residues (Glu2, Asp4, and Asp5), which will always try to extend into the aqueous phase and therefore act as a hydrophilic anchor. The amphipathic and the hydrophobic transmembrane part contain the most important hydrophobic anchoring elements. In addition there are specific aromatic and charged amino acid residues in these domains (Phe 11, Tyr21, Tyr24, Trp26, Phe42, Phe45, Lys40, Lys43, and Lys44) that fine-tune the association of the protein to the lipid bilayer. The interfacial Tyr residues are important recognition elements for precise protein positioning, a function that cannot be performed optimally by residues with an aliphatic character. The Trp26 anchor is not very strong: depending on the context, the tryptophan residue may move in or out of the membrane. On the other hand, Lys residues and Phe residues at the C-terminus of the protein act in a unique concerted action to strongly anchor the protein in the lipid bilayer.
噬菌体M13主要衣壳蛋白被广泛用作研究膜蛋白的生物物理、生物化学和分子生物学参考系统。该蛋白具有多个控制其在脂质双层中位置和方向的元件。N端主要存在带负电荷的氨基酸残基（Glu2、Asp4和Asp5），这些残基总是试图延伸到水相中，因此起到亲水锚的作用。两亲性和疏水跨膜部分包含最重要的疏水锚定元件。此外，这些结构域中还有特定的芳香族和带电荷的氨基酸残基（Phe 11、Tyr21、Tyr24、Trp26、Phe42、Phe45、Lys40、Lys43和Lys44），它们微调蛋白与脂质双层的结合。界面处的Tyr残基是精确蛋白定位的重要识别元件，这一功能无法由具有脂肪族性质的残基最佳地执行。Trp26锚定不是很强：根据具体情况，色氨酸残基可能会移入或移出膜。另一方面，蛋白C端的Lys残基和Phe残基以独特的协同作用将蛋白牢固地锚定在脂质双层中。
