Xenopus oocytes oocyte collection

Researchers at Aventis described a pharmacophore for Kvl.5 channel blockers consisting of three hydrophobic centers in a triangular arrangement. First observed in an earlier active series [73], the pharmacophore was validated using a database of 423 Kvl.5 blockers [74], The query was able to retrieve 58% of the known actives. A pharmacophore search of the corporate collection identified 27 clusters containing 1975 compounds. Screening the representatives of 18 clusters led to the discovery of an anthranilamide hit molecule (Kvl.5 IC50 = 5.6pM in Xenopus oocytes) [74],... 

Further studies revealed that vertebrate cells contain three proteins that can function like cyclin B to stimulate Xenopus oocyte maturation two closely related cyclin Bs and cyclin A. Collectively called B-type cyclins, these proteins exhibit regions of high sequence homology. (B-type cyclins are distinguished from Gi cyclins described in Section 21.5.) In intact cells, degradation of all the B-type cyclins begins after the onset of anaphase, the period of mitosis when sister chromatids are separated and pulled toward opposite spindle poles. 

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