1m00: Difference between revisions

[[Image:1m00.gif|left|200px]]<br /><applet load="1m00" size="350" color="white" frame="true" align="right" spinBox="true"  

A series of N-alkyl-N'-hydroxyguanidine compounds have recently been characterized as non-amino acid substrates for all three nitric oxide synthase (NOS) isoforms which mimic NO formation from N(omega)-hydroxy-L-arginine. Crystal structures of the nNOS heme domain complexed with either N-isopropyl-N'-hydroxyguanidine or N-butyl-N'-hydroxyguanidine reveal two different binding modes in the substrate binding pocket. The binding mode of the latter is consistent with that observed for the substrate N(omega)-hydroxy-L-arginine bound in the nNOS active site. However, the former binds to nNOS in an unexpected fashion, thus providing new insights into the mechanism on how the hydroxyguanidine moiety leads to NO formation. Structural features of substrate binding support the view that the OH-substituted guanidine nitrogen, instead of the hydroxyl oxygen, is the source of hydrogen supplied to the active ferric-superoxy species for the second step of the NOS catalytic reaction.

1M00 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus] with <scene name='pdbligand=ACT:'>ACT</scene>, <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=HEM:'>HEM</scene>, <scene name='pdbligand=H4B:'>H4B</scene> and <scene name='pdbligand=BHH:'>BHH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Nitric-oxide_synthase Nitric-oxide synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.13.39 1.14.13.39] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M00 OCA].  

[[Category: Poulos, T L.]]

[[Category: Wang, P G.]]

[[Category: Wen, E Z.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:50:04 2008''