2hrp
From Proteopedia
(New page: 200px<br /> <applet load="2hrp" size="450" color="white" frame="true" align="right" spinBox="true" caption="2hrp, resolution 2.2Å" /> '''ANTIGEN-ANTIBODY COM...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:2hrp.gif|left|200px]]<br /> | + | [[Image:2hrp.gif|left|200px]]<br /><applet load="2hrp" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="2hrp" size=" | + | |
caption="2hrp, resolution 2.2Å" /> | caption="2hrp, resolution 2.2Å" /> | ||
'''ANTIGEN-ANTIBODY COMPLEX'''<br /> | '''ANTIGEN-ANTIBODY COMPLEX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | F11.2.32, a monoclonal antibody raised against HIV-1 protease (Kd = 5 nM), which inhibits proteolytic activity of the enzyme (K(inh) = 35(+/-3)nM), has been studied by crystallographic methods. The three-dimensional | + | F11.2.32, a monoclonal antibody raised against HIV-1 protease (Kd = 5 nM), which inhibits proteolytic activity of the enzyme (K(inh) = 35(+/-3)nM), has been studied by crystallographic methods. The three-dimensional structure of the complex between the Fab fragment and a synthetic peptide, spanning residues 36 to 46 of the protease, has been determined at 2.2 A resolution, and that of the Fab in the free state has been determined at 2.6 A resolution. The refined model of the complex reveals ten well-ordered residues of the peptide (P36 to P45) bound in a hydrophobic cavity at the centre of the antigen-binding site. The peptide adopts a beta hairpin-like structure in which residues P38 to P42 form a type II beta-turn conformation. An intermolecular antiparallel beta-sheet is formed between the peptide and the CDR3-H loop of the antibody; additional polar interactions occur between main-chain atoms of the peptide and hydroxyl groups from tyrosine residues protruding from CDR1-L and CDR3-H. Three water molecules, located at the antigen-antibody interface, mediate polar interactions between the peptide and the most buried hypervariable loops, CDR3-L and CDR1-H. A comparison between the free and complexed Fab fragments shows that significant conformational changes occur in the long hypervariable regions, CDR1-L and CDR3-H, upon binding the peptide. The conformation of the bound peptide, which shows no overall structural similarity to the corresponding segment in HIV-1 protease, suggests that F11.2.32 might inhibit proteolysis by distorting the native structure of the enzyme. |
==About this Structure== | ==About this Structure== | ||
| - | 2HRP is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http:// | + | 2HRP is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HRP OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 13: | ||
[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
| - | [[Category: Bentley, G | + | [[Category: Bentley, G A.]] |
[[Category: Lescar, J.]] | [[Category: Lescar, J.]] | ||
[[Category: complex (immunoglobulin/peptide)]] | [[Category: complex (immunoglobulin/peptide)]] | ||
| Line 22: | Line 21: | ||
[[Category: hiv1 protease]] | [[Category: hiv1 protease]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:45:01 2008'' |
Revision as of 15:45, 21 February 2008
|
ANTIGEN-ANTIBODY COMPLEX
Overview
F11.2.32, a monoclonal antibody raised against HIV-1 protease (Kd = 5 nM), which inhibits proteolytic activity of the enzyme (K(inh) = 35(+/-3)nM), has been studied by crystallographic methods. The three-dimensional structure of the complex between the Fab fragment and a synthetic peptide, spanning residues 36 to 46 of the protease, has been determined at 2.2 A resolution, and that of the Fab in the free state has been determined at 2.6 A resolution. The refined model of the complex reveals ten well-ordered residues of the peptide (P36 to P45) bound in a hydrophobic cavity at the centre of the antigen-binding site. The peptide adopts a beta hairpin-like structure in which residues P38 to P42 form a type II beta-turn conformation. An intermolecular antiparallel beta-sheet is formed between the peptide and the CDR3-H loop of the antibody; additional polar interactions occur between main-chain atoms of the peptide and hydroxyl groups from tyrosine residues protruding from CDR1-L and CDR3-H. Three water molecules, located at the antigen-antibody interface, mediate polar interactions between the peptide and the most buried hypervariable loops, CDR3-L and CDR1-H. A comparison between the free and complexed Fab fragments shows that significant conformational changes occur in the long hypervariable regions, CDR1-L and CDR3-H, upon binding the peptide. The conformation of the bound peptide, which shows no overall structural similarity to the corresponding segment in HIV-1 protease, suggests that F11.2.32 might inhibit proteolysis by distorting the native structure of the enzyme.
About this Structure
2HRP is a Protein complex structure of sequences from Mus musculus. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of an Fab-peptide complex: structural basis of HIV-1 protease inhibition by a monoclonal antibody., Lescar J, Stouracova R, Riottot MM, Chitarra V, Brynda J, Fabry M, Horejsi M, Sedlacek J, Bentley GA, J Mol Biol. 1997 Apr 18;267(5):1207-22. PMID:9150407
Page seeded by OCA on Thu Feb 21 17:45:01 2008
