TY - JOUR
T1 - The conformation of angiotensin II in solution. III. An analysis of Gd3+-induced perturbations of the 1H nmr spectrum
AU - Lenkinski, R. E.
AU - Stephens, R. L.
N1 - Funding Information:
The nmt experimentsd esuihedi n this report werep erformeda t the nmr Core Facility in the Com-prehensiveC ancerC entero f the Universityo f Alabamai n Binninghamo peratedu ndera grant from the U.S. Public Health SetviceC A-13148(John R. Durant.M .D.. /. D. Clickson,P h.D.), and at the Middle Atlnntii nmr FaciL-& Universityo f PennsylvaniaP. hitidelphia,P A, operatedu ndera grant jivm the U.S. P&b& Health ServiceR R-542. This work was supportedb y a grant from the US. Public HeaZth Service AM-22 980 (R_E.L.) and by a Postdoctoral FeZZowship of the iVational Library of Medicine, U.S. Public Health ServiceG rant L&f 0701103 (RLS.). The authors would like to thank Dr. J. D. Glicksonf or many heIpfu1d iscussions.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1981
Y1 - 1981
N2 - The interactions of human angiotensin II (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe) with Eu3+, La3+, and Gd3+ are monitored in H2O and D2O by 1H nmr. The peptide forms 1:1 complexes with the trivalent lanthanide ions in which the carboxyl groups of Asp-1 and Phe-8 form the metal binding site. Addition of La3+ induces no significant perturbations in the CαH-NH coupling constants or chemical shifts of the low field resonances of the peptide, indicating that the conformation of the interior residues of the peptide backbone is unchanged upon metal complexation. The addition of Gd3+ induces differential line-broadening of the resonances of the angiotensin II spectrum. These perturbations are discussed qualitatively in terms of the relative distance of each residue from the metal-binding site, and calculations are performed to estimate the absolute metal-proton distances for six of the hydrogens in the hormone (the NH's of Val-2, Tyr-4, Ile-5, His-6, and Phe-8, and the C2-H of the His-6 imidazole). Various literature models for the conformation of the hormone is aqueous solution are discussed in terms of their consistency with these distances.
AB - The interactions of human angiotensin II (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe) with Eu3+, La3+, and Gd3+ are monitored in H2O and D2O by 1H nmr. The peptide forms 1:1 complexes with the trivalent lanthanide ions in which the carboxyl groups of Asp-1 and Phe-8 form the metal binding site. Addition of La3+ induces no significant perturbations in the CαH-NH coupling constants or chemical shifts of the low field resonances of the peptide, indicating that the conformation of the interior residues of the peptide backbone is unchanged upon metal complexation. The addition of Gd3+ induces differential line-broadening of the resonances of the angiotensin II spectrum. These perturbations are discussed qualitatively in terms of the relative distance of each residue from the metal-binding site, and calculations are performed to estimate the absolute metal-proton distances for six of the hydrogens in the hormone (the NH's of Val-2, Tyr-4, Ile-5, His-6, and Phe-8, and the C2-H of the His-6 imidazole). Various literature models for the conformation of the hormone is aqueous solution are discussed in terms of their consistency with these distances.
UR - http://www.scopus.com/inward/record.url?scp=0019857305&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0019857305&partnerID=8YFLogxK
U2 - 10.1016/S0162-0134(00)80295-0
DO - 10.1016/S0162-0134(00)80295-0
M3 - Article
AN - SCOPUS:0019857305
SN - 0162-0134
VL - 15
SP - 95
EP - 111
JO - Journal of Inorganic Biochemistry
JF - Journal of Inorganic Biochemistry
IS - 2
ER -