Pyridoxal phosphate-dependent reactions in water pools.

Pyridoxal 5'-phosphate, its Schiff base with L-alanine, and cytosolic aspartate aminotransferase were dissolved in isooctane solutions containing reverse micelles of the surfactant di-2-ethylhexylsodium sulfosuccinate and water. The physico-chemical properties of these compounds in the new environment have been studied.

Metabolism of straight saturated medium chain length (C9 to C12) dicarboxylic acids.

A method utilizing thin-layer chromatography, high performance liquid chromatography, and mass spectrometry was developed for the quantification of C9, C10, C11, and C12 dicarboxylic acids in serum, urine, and feces of human volunteers and rats after oral administration of the acids. The method allowed good resolution and measurement of the dicarboxylic acids at nanogram levels. In humans, excretion was independent of the dosage; about 60% of C9, 17% of C10, 5% of C11, and 1% of C12 were excreted in the urine during the first 12 hours after administration.

X-ray absorption near edge structure (XANES) determination of calcium sites of troponin C and parvalbumin.

Using synchrotron radiation at the Frascati storage ring ADONE, the X-ray Absorption Near Edge Structure (XANES) has been applied to determine homologies and modifications of the local structure of the calcium binding sites of troponin C. In all four calcium binding sites, Ca2+ appears to be co-ordinated to carboxyl and carbonyl groups in a characteristic configuration. No structural difference has been found between high and low-affinity sites.