1pph: Difference between revisions

[[Image:1pph.gif|left|200px]]<br /><applet load="1pph" size="350" color="white" frame="true" align="right" spinBox="true"  

The X-ray crystal structures of the complexes formed with bovine trypsin and the N alpha-tosylated piperidides of m-amidino-, p-amidino- and p-guanidino-D,L-phenylalanine (3-TAPAP, 4-TAPAP and 4-TGPAP) were determined with data to 1.8 A resolution. The L-stereoisomer of 3-TAPAP binds as a compact entity into the active site of trypsin, with the amidino and the carbonyl groups of the central amidinophenylalanyl residue hydrogen-bonded to Gly216 of trypsin. According to modeling and energy minimization, 3-TAPAP fits perfectly in this conformation to the more restrictive thrombin active site also (Bajusz et al. (1978) Int. J. Pept. Prot. Res. 12, 217-221); the piperidine moiety extends into the cage-like S2 subsite of thrombin, but leaves room for additional substituents which might help to improve binding and pharmacological properties. In contrast, 4-TAPAP and 4-TGPAP bind only weakly and in an extended conformation to trypsin; their considerably enhanced affinities for thrombin would suggest a more compact binding to thrombin.

1PPH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=APM:'>APM</scene> and <scene name='pdbligand=TOS:'>TOS</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Trypsin Trypsin], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.4 3.4.21.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PPH OCA].  

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:31:10 2008''