Related Articles1H/15N HSQC NMR studies of ligand carboxylate group interactions with arginine residues in complexes of brodimoprim analogues and Lactobacillus casei dihydrofolate reductase.
1H and 15N NMR studies have been undertaken on complexes of Lactobacillus casei dihydrofolate reductase (DHFR) formed with analogues of the antibacterial drug brodimoprim (2,4-diamino-5-(3', 5'-dimethoxy-4'-bromobenzyl)pyrimidine) in order to monitor interactions between carboxylate groups on the ligands and basic residues in the protein. These analogues had been designed by computer modeling with carboxylated alkyl chains introduced at the 3'-O position in order to improve their binding properties by making additional interactions with basic groups in the protein. Specific interactions between ligand carboxylate groups and the conserved Arg57 residue have been detected in studies of 1H/15N HSQC spectra of complexes of DHFR with both the 4-carboxylate and the 4, 6-dicarboxylate brodimoprim analogues. The spectra from both complexes showed four resolved signals for the four NHeta protons of the guanidino group of Arg57, and this is consistent with hindered rotation in the guanidino group resulting from interactions with the 4-carboxylate group in each analogue. In the spectra of each complex, one of the protons from each of the two NH2 groups and both nitrogens are considerably deshielded compared to the shielding values normally observed for such nuclei. This pattern of deshielding is that expected for a symmetrical end-on interaction of the carboxylate oxygens with the NHeta12 and NHeta22 guanidino protons. The differences in the degree of deshielding between the complexes of the two structurally similar brodimoprim analogues and the methotrexate indicates that the shielding is very sensitive to geometry, most probably to hydrogen bond lengths. The 1H/15N HSQC spectrum of the DHFR complex with the brodimoprim-6-carboxylate analogue does not feature any deshielded Arg NHeta protons and this argues against a similar interaction with the Arg57 in this case. It has not proved possible to determine whether the 6-carboxylate in this analogue is interacting directly with any residue in the protein. 1H/15N HSQC spectra have been fully assigned for the complexes with the three brodimoprim analogues and chemical shift mapping used to explore interactions in the binding site. The 1H signals of the bound ligands for all three brodimoprim analogues have been assigned. Their 1H chemical shifts were found to be fairly similar in the different complexes indicating that the 2, 4-diaminopyrimidine and the benzyl ring are binding in essentially the same binding sites and with the same overall conformation in the different complexes. The rotation rate about the NepsilonCzeta bond in the brodimoprim-4,6-dicarboxylate complex with DHFR has been determined from a zz-HSQC exchange experiment, and its value is quite similar to that observed in the DHFR.methotrexate complex (24 +/- 10 s-1 at 8 degrees C and 50 +/- 10 s-1 at 15 degrees C, respectively). The 1H and 15N chemical shift differences of selected amide and guanidino NH groups, measured between the DHFR complexes, provided further evidence about the interactions involving Arg57 with the 4-carboxylate and 4,6-dicarboxylate brodimoprim analogues.
[NMR paper] NMR studies of protein-ligand interactions.
NMR studies of protein-ligand interactions.
Related Articles NMR studies of protein-ligand interactions.
Methods Mol Biol. 2005;305:197-214
Authors: Maurer T
Interaction between biological macromolecules or of macromolecules with low-molecular-weight ligands is a central paradigm in the understanding of function in biological systems. It is also the major goal in pharmaceutical research to find and optimize ligands that modulate the function of biological macromolecules. Both technological advances and new methods in the field of nuclear...
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[NMR paper] Studies of protein-ligand interactions by NMR.
Studies of protein-ligand interactions by NMR.
Related Articles Studies of protein-ligand interactions by NMR.
Biochem Soc Trans. 2003 Oct;31(Pt 5):1006-9
Authors: Clarkson J, Campbell ID
Solution-state NMR has become an accepted method for studying the structure of small proteins in solution. This has resulted in over 3000 NMR-based co-ordinate sets being deposited in the Protein Databank. It is becoming increasingly apparent, however, that NMR is also a very powerful tool for accessing interactions between macromolecules and various ligands....
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Arginine interactions with anatase TiO(2) (100) surface and the perturbation of (49)T
Arginine interactions with anatase TiO(2) (100) surface and the perturbation of (49)Ti NMR chemical shifts - a DFT investigation: relevance to Renu-Seeram bio solar cell.
Related Articles Arginine interactions with anatase TiO(2) (100) surface and the perturbation of (49)Ti NMR chemical shifts - a DFT investigation: relevance to Renu-Seeram bio solar cell.
J Mol Model. 2010 Sep 21;
Authors: Koch R, Lipton AS, Filipek S, Renugopalakrishnan V
Density functional theoretical calculations have been utilized to investigate the interaction of the amino...
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[NMR paper] Studies of protein-ligand interactions by NMR.
Studies of protein-ligand interactions by NMR.
Related Articles Studies of protein-ligand interactions by NMR.
Methods Mol Biol. 1997;60:195-232
Authors: Craik DJ, Wilce JA
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[NMR paper] Studies of protein-ligand interactions by NMR.
Studies of protein-ligand interactions by NMR.
Related Articles Studies of protein-ligand interactions by NMR.
Methods Mol Biol. 1997;60:195-232
Authors: Craik DJ, Wilce JA
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[NMR paper] Dynamic NMR studies of ligand-receptor interactions: design and analysis of a rapidly
Dynamic NMR studies of ligand-receptor interactions: design and analysis of a rapidly exchanging complex of FKBP-12/FK506 with a 24 kDa calcineurin fragment.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www3.interscience.wiley.com-aboutus-images-wiley_interscience_pubmed_logo_FREE_120x27.gif http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--www.pubmedcentral.nih.gov-corehtml-pmc-pmcgifs-pubmed-pmc.gif Related Articles Dynamic NMR studies of ligand-receptor interactions: design and analysis of a rapidly exchanging complex of FKBP-12/FK506 with a 24 kDa calcineurin...
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[NMR paper] On the ligand-protein and ligand-flavin interactions in NADPH-adrenodoxin reductase a
On the ligand-protein and ligand-flavin interactions in NADPH-adrenodoxin reductase as studied by 31P- and 13C-NMR. Use of 13C-enriched FAD as a probe.
Related Articles On the ligand-protein and ligand-flavin interactions in NADPH-adrenodoxin reductase as studied by 31P- and 13C-NMR. Use of 13C-enriched FAD as a probe.
J Biochem. 1991 Jan;109(1):144-9
Authors: Fujii S, Nonaka Y, Okamoto M, Miura R
The interaction between 2',5'-ADP and NADPH-adrenodoxin reductase from bovine adrenocortical mitochondria was examined by titrating the enzyme with...