钾通道 Kv1.2/2.1 嵌合体的晶体结构。双层脂膜的计算烃边界是由红色和蓝色点表示。]]
膜蛋白()是指能够结合或整合到细胞或细胞器的膜上的蛋白质的总称。而细胞中一半以上的蛋白质可以与膜以不同形式结合。根据与膜结合强度的不同以及位置,膜蛋白可以被分为三类:'(或称外周膜蛋白)、整合膜蛋白和'。
主要类型
*整合膜蛋白是镶嵌在磷脂双分子层上的蛋白质,总是与膜结合在一起,往往可多次跨膜,形成多个α-螺旋构成的跨膜通道。可以定义为需要通过人工加入去垢剂(如SDS或Triton X-100)或其他非极性溶剂才能够从膜中分离出来的蛋白质。其跨膜結構域通常是由20-25个非极性氨基酸组成的α-螺旋结构,而亲水结构域则伸出细胞质面和膜的外表面。内在膜蛋白还可以根据与双分子膜之间结合关系的差异细分为:
**跨膜蛋白,顾名思义即跨越膜的两端的蛋白质,其跨膜結構域常为α-螺旋,也有一部分跨膜蛋白以β-折叠形成桶装跨膜通道。
**单向整合膜蛋白,其只从一个方向(膜外或膜内)与膜结合,虽然部分插入膜中,但不跨膜。
***'是能够暂时与膜或整合膜蛋白结合的蛋白质,主要是通过疏水、静电和其他非共价相互作用来进行结合,这种结合可以通过加入极性试剂,如高pH或高盐溶液来破坏。
***'是膜蛋白以共价键与脂相连,并以脂肪酸链插入膜中,细胞外表面和胞质面都存在
内在膜蛋白和外在膜蛋白都可以被翻译后修饰,如加上脂肪酸链和,有助于与脂膜的结合。
参见
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**跨膜蛋白
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*离子通道
*受体 (生物化学)
参考文献
书籍
- 吴光耀 主编:《精英教案》,军事宜文出版社,2005
延伸阅读
*Protein-lipid interactions (Ed. L.K. Tamm) Wiley, 2005.
Popot J-L. and Engelman D.M. 2000. Helical membrane protein folding, stability, and evolution. Annu. Rev. Biochem.* 69: 881-922.
Bowie J.U. 2005. Solving the membrane protein folding problem. Nature* 438: 581-589.
Cho, W. and Stahelin, R.V. 2005. Membrane-protein interactions in cell signaling and membrane trafficking. Annu. Rev. Biophys. Biomol. Struct.* 34: 119–151.
Goni F.M. 2002. Non-permanent proteins in membranes: when proteins come as visitors. Mol. Membr. Biol.* 19: 237-245.
Johnson J.E. and Cornell R.B. 1999. Amphitropic proteins: regulation by reversible membrane interactions. Mol. Membr. Biol.* 16: 217-235.
Seaton B.A. and Roberts M.F. Peripheral membrane proteins. pp. 355–403. In Biological Membranes* (Eds. K. Mertz and B.Roux), Birkhauser Boston, 1996.
外部链接
組織
*[http://memprotein.org Membrane Protein Structural Dynamics Consortium]
*[http://www.uwmembraneproteins.org Transmembrane Protein Center] at University of Wisconsin-Madison
膜蛋白質資料庫
*[https://web.archive.org/web/20110411070708/http://blanco.biomol.uci.edu/Membrane_Proteins_xtal.html List of transmembrane proteins of known 3D structure]
*[https://web.archive.org/web/20140103031444/http://tcdb.org/ TCDB] - Transporter Classification database
*[https://web.archive.org/web/20140103112750/http://opm.phar.umich.edu/ Orientations of Proteins in Membranes (OPM) database] 3D structures of integral and peripheral membrane proteins arranged in the lipid bilayer
*[http://www.mpdb.tcd.ie/ Membrane PDB] Database of 3D structures of integral membrane proteins and hydrophobic peptides with an emphasis on crystallization conditions
*[https://web.archive.org/web/20131225065028/http://pdbtm.enzim.hu/ Protein Data Bank of Transmembrane Proteins] 3D models of all transmembrane proteins currently in PDB. Approximate positions of membrane boundary planes were calculated for each PDB entry.
*[https://web.archive.org/web/20140103120108/http://membranetransport.org/ TransportDB] Genomics-oriented database of transporters from TIGR
*[https://web.archive.org/web/20120921002258/http://proteomics.bioengr.uic.edu/metador/MeTaDoR.html Membrane targeting domains (MeTaDoR)]
延伸閱讀
- [http://www.biomedcentral.com/1741-7007/7/50 The Human Membrane Proteome] - A comprehensive article covering the transmembrane protein component of the human proteome
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