Search

The effects of antibodies to the glycoprotein Ib (GPIb) and the seven transmembrane domain receptor (STDR) on thrombin binding and changes in Ca2+ concentration induced by alpha-thrombin or the tethered ligand peptide SFLLRNPNDKYEPF were examined by monitoring the binding activity in three different types of platelet preparations. Curve-fitting analyses showed a slow rate of increase in Ca2+ concentration in the preparation not blocked by monoclonal antibodies, indicating that both GPIb and STDR are essential in platelet activation over a wide range of thrombin concentrations.

The changes in platelet cytoplasmic Ca2+ concentration induced by alpha-thrombin or the tethered ligand peptide SFLLRNPNDKYEPF following treatment either with human polymorphonuclear leukocyte elastase or with Serratia marcescens protease were examined. The results were analyzed in accordance with the roles of glycoprotein Ib (GPIb) and the seven transmembrane domain receptor (STDR) in blood platelet activation. An analysis of the patterns of degradation of GPIb and STDR showed that the form of GPIb functioning as a high-affinity receptor for alpha-thrombin exhibits greater sensitivity to Serratia protease degradation than the form that mediates the initial adhesion of platelets to von Willebrand factor.

An accessible and simple fluorescent dT analogue is demonstrated to effectively probe the DNA microenvironment and display different emission in a duplex versus single-stranded oligonucleotides. The synthesis and photophysical characteristics of a series of simple and responsive thymidine analogues, where a 2'-deoxy-U core is conjugated to aromatic five-membered heterocycles, including furan, thiophene, oxazole, thiazle is described.

A minimally disruptive fluorescent dC analog provides a rapid and non-destructive method for in vitro detection of G, 8-oxoG, and T, the downstream transverse mutation product.