Evidence and nature of a novel thiol-oxidase in human platelets.

The study, addressed to understand whether or not human platelets possess a unique thiol-oxidase whose activity could be modulated by signalling pathway initiated upon the activation of Receptor-'C'k revealed the existence of disulphide-dependent oxidation within these cells and this phenomenon was regulated by Receptor-'C'k-dependent generation of second messengers especially phosphatidic acid(PA); cAMP and cGMP. Purification of this activity revealed the existence of 47 kDa protein having thiol-oxidase activity. Keeping in view these results we propose that the existence of this novel 47 kDa Thiol-oxidase within human platelets may provide a 'crucial switch' for the regulation of Receptor-'C'k-dependent mevalonate pathway in human platelets.