Biomaterial Database

Correlation between 15N NMR chemical shifts in proteins and secondary structure. 1994

H Le, and E Oldfield

Department of Chemistry, University of Illinois at Urbana-Champaign 61801.

An empirical correlation between the peptide 15N chemical shift, delta 15Ni, and the backbone torsion angles phi i, psi i-1 is reported. By using two-dimensional shielding surfaces delta (phi i, psi i-1), it is possible in many cases to make reasonably accurate predictions of 15N chemical shifts for a given structure. On average, the rms error between experiment and prediction is about 3.5 ppm. Results for threonine, valine and isoleucine are worse (approximately 4.8 ppm), due presumably to chi 1-distribution/gamma-gauche effects. The rms errors for the other amino acids are approximately 3 ppm, for a typical maximal chemical shift range of approximately 15-20 ppm. Thus, there is a significant correlation between 15N chemical shift and secondary structure.

UI	MeSH Term	Description	Entries
D008433	Mathematics	The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Mathematic
D009587	Nitrogen Isotopes	Stable nitrogen atoms that have the same atomic number as the element nitrogen but differ in atomic weight. N-15 is a stable nitrogen isotope.	Nitrogen Isotope,Isotope, Nitrogen,Isotopes, Nitrogen
D009682	Magnetic Resonance Spectroscopy	Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).	In Vivo NMR Spectroscopy,MR Spectroscopy,Magnetic Resonance,NMR Spectroscopy,NMR Spectroscopy, In Vivo,Nuclear Magnetic Resonance,Spectroscopy, Magnetic Resonance,Spectroscopy, NMR,Spectroscopy, Nuclear Magnetic Resonance,Magnetic Resonance Spectroscopies,Magnetic Resonance, Nuclear,NMR Spectroscopies,Resonance Spectroscopy, Magnetic,Resonance, Magnetic,Resonance, Nuclear Magnetic,Spectroscopies, NMR,Spectroscopy, MR
D011506	Proteins	Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.	Gene Products, Protein,Gene Proteins,Protein,Protein Gene Products,Proteins, Gene
D004798	Enzymes	Biological molecules that possess catalytic activity. They may occur naturally or be synthetically created. Enzymes are usually proteins, however CATALYTIC RNA and CATALYTIC DNA molecules have also been identified.	Biocatalyst,Enzyme,Biocatalysts
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
D016208	Databases, Factual	Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.	Databanks, Factual,Data Banks, Factual,Data Bases, Factual,Data Bank, Factual,Data Base, Factual,Databank, Factual,Database, Factual,Factual Data Bank,Factual Data Banks,Factual Data Base,Factual Data Bases,Factual Databank,Factual Databanks,Factual Database,Factual Databases
D017433	Protein Structure, Secondary	The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to ALPHA-HELICES; BETA-STRANDS (which align to form BETA-SHEETS), or other types of coils. This is the first folding level of protein conformation.	Secondary Protein Structure,Protein Structures, Secondary,Secondary Protein Structures,Structure, Secondary Protein,Structures, Secondary Protein