Leroy M J, Dumler I, Lugnier C, Shushakova N D, Ferré F
INSERM U.361, Maternité Baudelocque, Paris, France.
Biochem Biophys Res Commun. 1992 Apr 30;184(2):700-5. doi: 10.1016/0006-291x(92)90646-3.
The cyclic nucleotide phosphodiesterase enzymatic system is examined in extracts of human myometrium and four individual phosphodiesterase isoforms have been isolated and characterized. A new thermostable peptide, recently purified in rat and calf myometrium, is able to stimulate up to 55-fold, the calcium-calmodulin dependent phosphodiesterase isoform. Activation of cAMP hydrolysis is by far the most marked with a 55-fold maximal stimulation at a concentration of 0.1 microM peptide and a IC50 value estimated at 30nM. For cGMP hydrolysis, the maximal effect (x25) obtained at 40nM peptide is lesser and the IC50 value is in the 10nM range. Furthermore, we verified that classical calmodulin antagonists such as calmidazolium or trifluoroperazine did not change stimulation of the calcium-calmodulin phosphodiesterase by the peptide, indicating that the myometrial peptide is different from calmodulin. To our knowledge, this is the first evidence for such a strong and selective stimulation of one isoform of the phosphodiesterase enzymatic system by a natural peptide.
对人子宫肌层提取物中的环核苷酸磷酸二酯酶酶系统进行了研究，已分离并鉴定出四种个体磷酸二酯酶同工型。最近在大鼠和小牛子宫肌层中纯化出一种新的耐热肽，它能够将钙调蛋白依赖性磷酸二酯酶同工型的活性刺激高达55倍。cAMP水解的激活作用最为显著，在肽浓度为0.1微摩尔时最大刺激倍数达55倍，估计IC50值为30纳摩尔。对于cGMP水解，在40纳摩尔肽时获得的最大效应（25倍）较小，IC50值在10纳摩尔范围内。此外，我们证实，诸如氯咪达唑或三氟拉嗪等经典钙调蛋白拮抗剂不会改变该肽对钙调蛋白磷酸二酯酶的刺激作用，这表明子宫肌层肽与钙调蛋白不同。据我们所知，这是天然肽对磷酸二酯酶酶系统的一种同工型进行如此强烈且选择性刺激的首个证据。
