BK通道特异的阻断剂
蕈青霉素(paxilline)是一种BK通道特异的阻断剂,能够有效缓解由BK-D434G功能获得所导致的失神癫痫和运动障碍。虽然蕈青霉素在一定程度上可以减轻这些症状,但由于其药物半衰期较短,控制效果持续时间有限。因此,未来需要开发药效更加持久的新药来针对BK离子通道。
生物活性
Paxilline 是一种来自Penicillium paxilli的吲哚生物碱霉菌毒素,通过封闭通道的阻断机制有效地抑制 BK 通道。此外,它也能抑制肌质网 Ca2+ 刺激的 ATP 酶 (SERCA),对不同亚型的 SERCA 的 IC50 值介于 5 μM-50 μM 之间。 Paxilline 还表现出显著的抗惊厥活性。
靶点
IC50: 5-50 μM (SERCA, BK channel)
中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
1'-O-乙酰基蕈青霉素 | 1'-O-acetylpaxilline | 121998-08-1 | C29H35NO5 | 477.601 |
—— | (2R,4bS,6aS,12bS,12cR,14aS)-9,10-diisopentenylpaxilline | 1445780-03-9 | C37H49NO4 | 571.8 |
—— | PC-M5' | 133613-75-9 | C29H37NO5 | 479.616 |
青霉震颤素 | Penitrem A | 12627-35-9 | C37H44ClNO6 | 634.212 |
A putative indole diterpene biosynthetic gene cluster composed of eight genes was identified in a genome database of Phomopsis amygdali, and from it, biosynthetic genes of fusicoccin A were cloned and characterized. The six genes showed significant similarities to pax genes, which are essential to paxilline biosynthesis in Penicillium paxilli. Recombinants of the three putative prenyltransferase genes in the cluster were overexpressed in Escherichia coli and characterized by means of in vitro experiments. AmyG is perhaps a GGDP synthase. AmyC and AmyD were confirmed to be prenyltransferases catalyzing the transfer of GGDP to IGP and a regular di-prenylation at positions 20 and 21 of paxilline, respectively. AmyD is the first know example of an enzyme with this function. The Km values for AmyD were calculated to be 7.6 ± 0.5 μM for paxilline and 17.9 ± 1.7 μM for DMAPP at a kcat of 0.12 ± 0.003/s.