Sub-second 2D NMR spectroscopy at sub-millimolar concentrations.

A recently proposed protocol enables the acquisition of two-dimensional nuclear magnetic resonance (2D NMR) spectra within a single scan. A promising application opened up by this new data acquisition mode concerns its combination with active nuclear polarization methods, whereby spectroscopy is carried out on analytes whose spin magnetizations have been significantly enhanced over their Boltzmann thermal values. The present paper explores the potential of such combination, with the acquisition of peptide and protein 2D NMR 1H correlation spectra recorded after the samples had been subject to laser-driven chemically induced dynamic nuclear polarization (CIDNP).

Photocatalytic degradation of pesticides and bio-molecules in water.

Two approaches are suggested for the acceleration of the photocatalytic oxidation of organic contaminants of water: acceleration by oxidants and photo-enhancement by dyes. These processes were examined with several substances: two widely applied herbicides, bromacil (a uracil) and metribuzin (a triazine), and three proteins, studied as models of biocontaminated waters. The effects of oxygen and hydrogen peroxide indicated two different reaction patterns of photo-oxidation of the herbicides.

Titanium dioxide photocatalyzed oxidation of proteins in biocontaminated waters.

The TiO2 photocatalyzed oxidation of the proteins serum albumin, ovalbumin and gamma globulin, is reported. All the amino acids were susceptible to photocatalytic oxidation. However, some were especially vulnerable.

A citrate-binding site in calmodulin.

Calmodulin (CaM) is a major Ca2+ messenger which, upon Ca2+ activation, binds and activates a number of target enzymes involved in crucial cellular processes. The dependence on Ca2+ ion concentration suggests that CaM activation may be modulated by low-affinity Ca2+ chelators. The effect on CaM structure and function of citrate ion, a Ca2+ chelator commonly found in the cytosol and the mitochondria, was therefore investigated.

CIDNP study of the aromatic side chain interactions in myotoxin alpha.

CIDNP and COSY measurements were applied to study aromatic side chain interactions and conformations in myotoxin alpha, a Crotalus venom toxin which acts as blocker of the Ca2+ influx in the sarcoplasmic reticulum calcium pump. New evidence for the existence of a hydrophobic aromatic cluster at the amino terminus was obtained. This cluster consists of Tyr1, His5, His10, and (possibly) F12.