chloramine-t and metaperiodate

Heparin cofactor II (HC II) is known as a bifunctional inhibitor inactivating trypsin- and chymotrypsin type proteases. Its inhibitory activity increases in the presence of heparin, dermatan sulfate and chondroitin E. In the present study the inhibitory activity of HC II was investigated as function of various dermatan sulfate fractions and its stability was tested against oxidation reagents similar to thus secreted by activated leucocytes. High affinity dermatan sulfate (DS) increased the antithrombin inhibition activity of HC II about 1000-fold in contrast to about 100-fold in the case of low affinity DS. Oxidation of HC II carbohydrate side chains with sodium periodate showed less inactivation effects than oxidation by chloramine T or ammonium peroxodisulfate.

Topics: Chloramines; Chymotrypsin; Dermatan Sulfate; Heparin Cofactor II; Periodic Acid; Thrombin; Tosyl Compounds

Bovine lutropin and its subunits were submitted to oxidation by sodium periodate or chloramine T. Methionine residues were easily oxidized but partial destruction of fucose was observed. After oxidation treatment most of the lutropin exhibits the same elution volume in gel filtration as the native hormone. Sucrose gradient sedimentation or gel filtration experiments show however that the oxidation of isolated subunits is accompanied by aggregation of conformational changes even in the case of porcine beta subunit which contains only one methionine residue, unit and intact alpha subunit exhibit very low residual activity.

Topics: Amino Acids; Animals; Cattle; Chloramines; Chromatography, Gel; Luteinizing Hormone; Methionine; Molecular Conformation; Oxidation-Reduction; Periodic Acid; Structure-Activity Relationship; Swine; Tosyl Compounds

Topics: Amino Acids; Anti-Infective Agents, Local; Chloramines; Halogens; Hydrocarbons, Halogenated; Periodic Acid; Serine; Threonine; Tosyl Compounds