Beginnings and early history of the International Conferences on Magnetic Resonance in Biological Systems: development of the basic ideas in the field.

The early history of the principal meeting in the field of biological NMR spectroscopy, the International Conference on Magnetic Resonance in Biological Systems (ICMRBS), is presented from the perspective of one of the founders.

Predicting 15N chemical shifts in proteins using the preceding residue-specific individual shielding surfaces from phi, psi i-1, and chi 1 torsion angles.

Empirical shielding surfaces are most commonly used to predict chemical shifts in proteins from known backbone torsion angles, phi and psi. However, the prediction of (15)N chemical shifts using this technique is significantly poorer, compared to that for the other nuclei such as (1)H(alpha), (13)C(alpha), and (13)C(beta). In this study, we investigated the effects from the preceding residue and the side-chain geometry, chi(1), on (15)N chemical shifts by statistical methods.

Surface plasmon resonance studies of wild-type and AV77 tryptophan repressor resolve ambiguities in super-repressor activity.

The interactions of wild-type (WT) and AV77 tryptophan repressor (TR) with several operators have been studied using surface plasmon resonance. The use of this real-time method has been able to settle several outstanding issues in the field, in a way that has heretofore not been possible. We resolve the issue of the super-repressor status of the AV77 aporepressor and find that in contrast to early studies, which found no significant difference in the binding constants in vitro to those of the WT, that there is indeed a clear difference in the binding constant that can simply account for the phenotype.

Investigation of the neighboring residue effects on protein chemical shifts.

In this study, we report nearest neighbor residue effects statistically determined from a chemical shift database. For an amino acid sequence XYZ, we define two correction factors, Delta((X)Y)n,s and Delta(Y(Z))n,s, representing the effects on Y's chemical shifts from the preceding residue (X) and the following residue (Z), respectively, where X, Y, and Z are any of the 20 naturally occurring amino acids, n stands for (1)H(N), (15)N, (1)H(alpha), (13)C(alpha), (13)C(beta), and (13)C' nuclei, and s represents the three secondary structural types beta-strand, random coil, and alpha-helix. A total of approximately 14400 Delta((X)Y)n,s and Delta(Y(Z))n,s, representing nearly all combinations of X, Y, Z, n, and s, have been quantitatively determined.