Main-chain-directed strategy for the assignment of /sup 1/H NMR spectra of proteins

Journal Article · Tue Sep 22 00:00:00 EDT 1987 · Biochemistry; (United States)

OSTI ID:5400402

Englander, S W; Wand, A J

A strategy for assigning the resonances in two-dimensional (2D) NMR spectra of proteins is described. The method emphasizes the analysis of through-space relationships between protons by use of the two-dimensional nuclear Overhauser effect (NOE) experiment. NOE patterns used in the algorithm were derived from a statistical analysis of the combinations of short proton-proton distances observed in the high-resolution crystal structures of 21 proteins. One starts with a search for authentic main-chain NH-C/sub ..cap alpha../H-C/sub ..beta../H J-coupled units, which can be found with high reliability. The many main-chain units of a protein are then placed in their proper juxtaposition by recognition of predefined NOE connectivity patterns. To discover these connectivities, the 2D NOE spectrum is examined, in a prescribed order, for the distinct NOE patterns characteristic of helices, sheets, turns, and extended chain. Finally, the recognition of a few amino acid side-chain types places the discovered secondary structure elements within the polypeptide sequences. Unlike the sequential assignment approach, the main-chain-directed strategy does not rely on the difficult task of recognizing many side-chain spin systems in J-correlated spectra, the assignment process is not in general sequential with the polypeptide chain, and the prescribed connectivity patterns are cyclic rather than linear. The latter characteristic avoids ambiguous branch points in the analysis and imposed an internally confirmatory property on each forward step.

• Research Organization: Univ. of Pennsylvania, Philadelphia
• OSTI ID: 5400402
• Journal Information: Biochemistry; (United States), Vol. 26:19
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
PROTEINS
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
ALGORITHMS
CYTOCHROMES
NMR SPECTRA
OVERHAUSER EFFECT
PROTONS
BARYONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
MAGNETIC RESONANCE
MATHEMATICAL LOGIC
NUCLEONS
ORGANIC COMPOUNDS
PIGMENTS
RESONANCE
SPECTRA
550601* - Medicine- Unsealed Radionuclides in Diagnostics