Conformation of Albumin Binding Sites are Disturbed in Schizophrenia

Aim:Investigate some properties of albumin binding sites in schizophrenic patients.Methods:Properties of serum albumin binding sites were studied using quenching of fluorescence of probe K-35 (N-carboxyphenylimide of dimethylaminonaphthalic acid) with nitrate anion. Serum samples were collected from 24 schizophrenic patients and 24 healthy volunteers.Results:In the absence of quencher specific probe fluorescence in patients was 1,4 times higher than in controls. Fluorescent quenching constant for probe bound to albumin was 2,5 L/mol in patients versus 4,6 L/mol in volunteers (p< 0,01). Fluorescent fraction assessable to quenching was significantly lower in patients than in volunteers. Fluorescent decay studies on S-60 synchrotron have revealed in patient's albumin the redistribution between long-lived and short-lived molecules of the probe with increase of the latter. There were found decrease of albumin accessible SH-groups in schizophrenic patients as compared with volunteers.Conclusions:In schizophrenic patients conformational state of albumin binding sites is significantly disturbed that can lead to changes in protein-ligand interaction and to damage of main albumin functions (transport and detoxification) and aggravation of endotoxicosis.

EPR and Fluorescence Spectroscopy in the Photodegradation Study of Arabian and Colombian Crude Oils

EPR and fluorescence spectroscopy were used to evaluate the degradation of crude oils of different origins that were submitted to photochemical weathering under tropical conditions. The EPR spectra obtained showed signals of the paramagnetic species: the vanadylVO2+ion and organic free radicals. A decrease in linewidth of free radical signals was observed for both oils irradiated for 100 hours with sunlight of 350 W/m2. The reduction in the linewidth of the free radical of 9.8% in Arabian oil and 18.5% in Colombian oil, as well as the decrease in radical numbers, indicated photochemical degradation, especially in Colombian oil. The linewidth narrowing corresponding to free radicals in the irradiated oils occurred due to the rearrangement among radicals and aromatic carbon consumption. The irradiated oils showed a reduction in the relative intensity of fluorescence of the aromatics with high molecular mass, polar aromatics, and asphaltene. The fluorescent fraction was reduced by 61% in Arabian oil and 72% in Colombian oil, corresponding to photochemical degradation of crude oil aromatic compounds.