Thermodynamic study on the complexation of dioxovanadium [V] with isoleucine and glycylglycine

The dissociation constants of isoleucine and glycylglycine have been determined using a suitable computer program which employs a nonlinear least squares method. The complexation of dioxovanadium [V] with glycylglycine was studied by a combination of potentiometric and spectrophotometric techniques in aqueous solution at 25 °C and 0.1 mol dm[-3] ionic strength [NaClO[-4] in the pH range 2.00 to 2.60. All of the calculations have been done by the computer program Excel 2000. Dioxovanadium [V] complexes formed by isoleucine in the pH range 1.30 to 2.5 and between t = 25 °C and 35 °C with one mole dm[-3] sodium perchlorate as the ionic medium, have been investigated potentiometrically and spectrophotometrically. Ultimately, the thermodynamic functions [delta G°, delta H°, delta S°] have been calculated for the complexation of dioxovanadium [V] with isoleucine

Molecular characterization of hair cuticle and its extracted proteins in seven mammalian species

Hair is an of the epidermis in mammals and consists of two large groups of human hair proteins. One is hard -keratins and the other is matrix proteins. The present investigation aimed to compare the ultrastructural of the hair scale using the scanning electron microscope, and the proteins and amino acids content of the keratin in seven mammalian species. The values of the hair thickness, x/y feret and hair pattern of the species in the present study confirm the presence of species-specific characteristics and ultra structural variation. The situation in man differs from the wild mammals due to damage of hair cuticle caused by mechanical abuse, exposure to ultraviolet radiation and chemical over processing. The maximum amount of extracted proteins from hair keratin was analyzed by SDS-PAGE. The electrophoretic patterns showed an overall degree of similarity. However, differences exist between species in the intensity of stain. Quantitatively, the electrophoretic patterns scanned and analyzed using gel protein analyzer. The results showed no difference between the molecular mass of some species, but different in molecular mass distribution. Amino acid composition of keratin of mammalian hair species of the present study showed some variation, especially for methionine, isoleucine, lysine and arginine. The other amino acids studied are significantly present in most hair. One of the later amino acid is cysteine. Cysteine is a very important due to the presence of disulfate cross-links