English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

ADP interacts with platelets to cause shape change, aggregation and inhibition of adenylate cyclase. Previous attempts to measure the binding of ADP to its receptor on intact platelets have been frustrated by the low ratio of specifically bound ADP to the ADP trapped in centrifuged pellets. Several 2-substituted derivatives of ADP have higher apparent affinities for the ADP receptor, improving this ratio. We have prepared 2-azido 5'-ADP from 2-chloroadenosine in 20% yield. It was more active than ADP as an antagonist of PGE1-induced elevation of cyclic AMP (Ki = 96 nM, cf ADP Ki = 760 nM) and also as an inducer of shape change and aggregation. 2-Azido [β32P]-5'-ADP (2.5 Ci/mmole) was prepared and used to study binding. Platelets were separated from plasma by centrifugation through silicone oil (1.023 gm/ml) in a modified Eppendorf centrifuge. Scatchard plots of the binding data were resolved into two linear components, one of zero affinity, corresponding to trapped plasma, measured independently with [14C] sucrose, and a high affinity component with apparent KD = 110-160 nM. There were 400-700 of these binding sites per platelet. 2-Azido 5'-ADP is photolysable with light at &lt;310 nm, forming a reactive nitrene potentially suitable for photoaffinity labelling. 2-Azido [β32P]-5'-ADP was photolysed in the presence of washed platelets which were subsequently rewashed, solubilized and electrophoresed on SDS-polyacrylamide gradient slabs. Several peaks of radioactivity were observed in the high molecular weight region of the gel (ca 100-250 kD) one of which was less labelled in the presence of excess ADP or ATP to block access of the label to the receptor.

The Number and Nature of ADP Receptors on Human Blood Platelets Determined with a Photoaffinity Label