The mechanism of separation of polythiolpeptides and metallopolythiolpeptides by covalent affinity chromatography

Quantitative determination of Cu-thionein from human fluids with application of solid-phase extraction on covalent affinity chromatography with thiol-disulphide interchange support

The aim of our investigation was to carry out quantitative isolation of Cu-thionein (Cu-Th) in human body fluids (urine, plasma and breast milk) in order to determine the level of exposure to heavy metals. In the experiment covalent affinity chromatography with thiol-disulphide interchange gel (CAC-TDI) was used as a solid phase extraction (SPE) support for preconcentration of Cu-thionein (Cu-Th) protein and Cu bonded with MT from water and human fluids samples. The present paper is a continuation of early experiments on the quantitation of Hg-thionein (Hg-Th), Cd-thionein (Cd-Th) and Zn-thionein (Zn-Th) in human body fluids such as urine, plasma and breast milk.

Application of covalent affinity chromatography with thiol-disulphide interchange for determination of environmental exposition to heavy metals based on the quantitative determination of Zn-thionein from physiological human fluids by indirect method based on analysis of metal contents

Intoxication with heavy metals results in numerous poisonings and diseases. They disturb metabolism of the system, are the source of cancer, degeneration changes and others. As a result of kidney damage the urine of people exposed to heavy metals contains different low molecular weight proteins, oligopeptides and amino acids, indicating pathological changes. One of the proteins is a very specific metallopolythiopolypeptide--metallothionein (MT). Based on earlier investigations, a very good correlations has been found between the contents of metallothionein in urine and plasma and the concentration of heavy metals in the blood, urine, kidneys, liver and brain and general in level of exposition to heavy metals. The aim of our investigations was to carry out quantitative isolation of Zn-thionein (Zn-Th), in order to determine the level of exposition to heavy metals. For Zn-Th protein isolation by covalent affinity chromatography with thiol-disulphide interchange (CAC-TDI) was applied, which is a modern technique of separation of a high affinity, good repeatability and reproducibility, allowing specific isolation of the thiol-proteins CAC-TDI gel was used as a solid-phase extraction (SPE) support for preconcentration of Zn-Th protein and Zn bonded with Zn-Th from water, rine, plasma and breast milk samples. The investigations showed unfavourable effect of the support on separation of thiol proteins and good correlation between the concentration of MTs protein added to water, plasma and urine and the concentration of protein indirectly determined via atomic absorption spectrometric (AAS) method, by preconcentration on SPE support metals formerly bound with MT protein and absorbed on CAC-TDI gel and calculated from metals concentration. The present paper is a continuation of earlier experiments on quantitation of Hg-thionein and Cd-thionein in physiological fluids and homogenates.

Application of covalent affinity chromatography with thiol-disulphide interchange for determination of environmental exposure to heavy metals based on the quantitative isolation of Cd-thionein from human breast milk

The aim of this study was to test a new chromatographic method for the quantitative determination of Cd-thionein (Cd-Th) in human breast milk, in order to determine the level of exposure to heavy metals. Cd-thionein was isolated by covalent affinity chromatography with thiol-disulphide interchange, which is a modern separation technique of high affinity, good repeatability and reproducibility, allowing specific isolation of the thiolproteins. The fundamentals of indirect determination of the contents of metallothionein protein from human milk were worked out through estimation of the quantities of cadmium bound with Cd-thionein and adsorbed on covalent affinity chromatography gel during a separation process.

Application of solid-phase extraction to the preconcentration of metallothionein and metals from physiological fluids

Solid-phase extraction (SPE) with covalent affinity chromatography with thiol-disulphide interchange (CAC-TDI) gels as sorbents were used for the preconcentration of Cd-thionein (Cd-Th), Zn-thionein (Zn-Th) and Cu-thionein (Cu-Th) proteins and Cd, Zn or Cu bonded with metallothioneins (MTs) from water, plasma and human urine samples. An indirect method of quantitation of MTs, based on the analysis of metal content, for the determination of MT in human body fluids is described. In experiments, different types of CAC-TDI gels were tested. The results showed a satisfactory correlation between the concentration of MT proteins added to water or physiological fluids and the concentration of protein indirectly determined via the concentration of metals by atomic absorption spectrometry.

The application of affinity chromatography for quantitative determination of metallothionein in physiological fluids by an indirect method based on analysis of metal contents

An indirect method, based on the analysis of metal contents, for the determination of metallothionein (MT) in body fluids is described. Affinity chromatography gel was used as a solid phase extraction (SPE) support for preconcentration of MT Proteins and metals bound to MT from spiked water and human urine samples. The results showed a good correlation between the concentration of MT proteins added to water or physiological human urine and the concentration of protein indirectly determined by atomic absorption spectrometry (AAS) recovered by the SPE-affinity chromatography technique and calculated from the metal concentration. The present method can be used in toxicological analysis for determination of MT concentration in physiological fluids in subjects exposed to heavy metals.