Václavíková E., Kvasnička F. (2013): Isotachophoretic determination of glucosamine and chondroitin sulphate in dietary supplements. Czech J. Food Sci., 31: 55–65. Glucosamine and chondroitin sulfate, components of normal cartilage, are used as ingredients in dietary supplements intended to treat osteoarthritis and/or to support joint health. Of concern is the documented lack of quality in many ...

We isolated the soluble forms of gamma-glutamyltransferase (EC 2.3.2.2; gamma-GT) from adult and fetal human liver and primary hepatoma and compared their properties. The Km value for L-gamma-glutamyl-p-nitroanilide and glycylglycine, the Ki for anthglutin, and the pH optimum were identical for the enzyme from all three sources. Nor were significant differences observed among the three in their...

Two Schiff base ligands L1and L2 were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1: 1electrolytes. The IR data ...

Staphylococcus simulans biovar staphylolyticus produces an extracellular glycylglycine endopeptidase (lysostaphin) that lyses other staphylococci by hydrolyzing the cross bridges in their cell wall peptidoglycans. The genes for endopeptidase (end) and endopeptidase resistance (epr) reside on plasmid pACK1. An 8.4-kb fragment containing end was cloned into shuttle vector pL150 and was then intro...

Collagen is one of the most important proteins containing mostly proline hydroxyproline and glycine. In collagen, approximately 33 percent of the amino acid residues are glycine and they occur at every third position, whereas remaining percentage is constituted by mainly proline or hydroxyproline and some part by alanine etc. having no definite positional placement in the chain. Thus, a study o...

Glycylglycine (Gly-Gly) transport across rabbit small intestinal brush border membrane vesicles was studied in the presence and absence of a Na+ gradient or a pH gradient. The transport was found to be entirely independent of Na+ but significantly stimulated by lowering extravesicular pH (pHo). The maximum stimulation was seen at pHo 5.5, where the uptake rate was about 2-times higher than the ...

1. Peptide-splitting enzymes have been studied in buffered glycerine extracts of larval salivary glands of three stocks of Drosophila melanogaster. 2. The ultraviolet absorption spectrum of the glycerine extracts indicates the presence of a considerable amount of nucleic acid. 3. Alanylglycine (AG), leucylglycine (LG), leucylglycylglycine (LGG), glycylglycine (GG), and diglycylglycine (GGG) are...

Carnosinase, the dipeptidase which hydrolyses carnosine and other histidine-containing dipeptides, was assayed in mucosal tissues of the human and of the rat gut. Kinetic properties of the intestinal enzyme were found to be similar to carnosinase of other animal tissues. Little or no activity was detected in human gastric or colonic mucosa, and the levels were lower in duodenal than jejunal muc...