Strategies for the use of lanthanide NMR shift probes in the determination of protein structure in solution

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · Biophys. J.; (United States)

DOI:https://doi.org/10.1016/S0006-3495(80)84933-2· OSTI ID:7032790

Lee, L; Sykes, B D

The homologous sequences observed for many calcium binding proteins such as parvalbumin, troponin c, the myosin light chains, and calmodulin has leand to the hypothesis that these proteins have homologous structures at the level of their calcium binding sites. This paper discusses the development of a nuclear magnetic resonance (NMR) technique which will enable us to test this structural hypothesis in solution. The technique involves the substitution of a paramagnetic lanthanide ion for the calcium ion which results in lanthanide induced shifts and broadening in the /sup 1/H NMR spectrum of the protein. These shifts are sensitive monitors of the precise geometrical orientation of each proton nucleus relative to the metal. The interaction of the lanthanide ytterbium with parvalbumin results in high resolution NMR spectra exhibiting a series of resonances with shifts spread over the range 32 to -19 ppM. The orientation and principal elements of the ytterbium magnetic susceptibility tensor have been determined using three assigned NMR resonances, the His-26 C2 and C4 protons and the amino terminal acetyl protons, and seven methyl groups; all with known geometry relative to the EF calcium binding site. The elucidation of these parameters has allowed us to compare the observed spectrum of the nuclei surrounding the EF calcium binding site of parvalbumin with that calculated from the x-ray struture. A significant number of the calculated shifts are larger than any of the observed shifts. We feel that a refinement of the x-ray based proton coordinates will be possible utilizing the geometric information contained in the lanthanide shifted NMR spectrum.

• Research Organization: Univ. of Alberta, Edmonton, AB (Canada)
• OSTI ID: 7032790
• Journal Information: Biophys. J.; (United States), Vol. 32:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
STRUCTURAL CHEMICAL ANALYSIS
NMR SPECTRA
SPECTRAL SHIFT
BIOCHEMICAL REACTION KINETICS
CALCIUM
CHEMICAL SHIFT
CRYSTALLOGRAPHY
GEOMETRY
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
RARE EARTHS
SPATIAL DEPENDENCE
X-RAY DIFFRACTION
ALKALINE EARTH METALS
COHERENT SCATTERING
DIFFRACTION
ELEMENTS
KINETICS
MAGNETIC RESONANCE
MATHEMATICS
METALS
ORGANIC COMPOUNDS
PROTEINS
REACTION KINETICS
RESONANCE
SCATTERING
SPECTRA
550200* - Biochemistry
551000 - Physiological Systems