Amiranoff B, Laburthe M, Dupont C, Rosselin G
Biochim Biophys Acta. 1978 Dec 18;544(3):474-81. doi: 10.1016/0304-4165(78)90321-5.
A vasoactive intestinal peptide-sensitive adenylate cyclase in intestinal epithelial cell membranes was characterized. Stimulation of adenylate cyclase activity was a function of vasoactive intestinal peptide concentration over a range of 1 . 10(-10)-1 . 10(-7) M and was increased six-times by a maximally stimulating concentration of vasoactive intestinal peptide. Half-maximal stimulation was observed with 4.1 +/- 0.7 nM vasoactive intestinal peptide. Fluoride ion stimulated adenylate cyclase activity to a higher extent than did vasoactive intestinal peptide. Under standard assay conditions, basal, vasoactive intestinal peptide- and fluoride-stimulated adenylate cyclase activities were proportional to time of incubation up to 15 min and to membrane concentration up to 60 microgram protein per assay. The vasoactive intestinal peptide-sensitive enzyme required 5-10 mM Mg2+ and was inhibited by 1 . 10(-5) M Ca2+. At sufficiently high concentrations, both ATP (3 mM) and Mg2+ (40 mM) inhibited the enzyme. Secretin also stimulated the adenylate cyclase activity from intestinal epithelial cell membranes but its effectiveness was 1/1000 that of vasoactive intestinal peptide. Prostaglandins E1 and E2 at 1 . 10(-5) M induced a two-fold increase of cyclic AMP production. Vasoactive intestinal peptide was the most potent stimulator of adenylate cyclase activity, suggesting an important physiological role of this peptide in the cyclic AMP-dependent regulation of the intestinal epithelial cell function.
对肠上皮细胞膜中一种对血管活性肠肽敏感的腺苷酸环化酶进行了特性分析。在1.10（-10）-1.10（-7）M的浓度范围内，腺苷酸环化酶活性的刺激是血管活性肠肽浓度的函数，并且在血管活性肠肽的最大刺激浓度下增加了6倍。在4.1±0.7 nM血管活性肠肽时观察到半数最大刺激。氟离子比血管活性肠肽更能刺激腺苷酸环化酶活性。在标准测定条件下，基础、血管活性肠肽和氟刺激的腺苷酸环化酶活性在孵育时间长达15分钟时与孵育时间成正比，在每次测定中膜浓度高达60微克蛋白质时与膜浓度成正比。血管活性肠肽敏感酶需要5-10 mM Mg2+，并被1.10（-5）M Ca2+抑制。在足够高的浓度下，ATP（3 mM）和Mg2+（40 mM）都抑制该酶。促胰液素也刺激肠上皮细胞膜的腺苷酸环化酶活性，但其效力是血管活性肠肽的1/1000。1.10（-5）M的前列腺素E1和E2使环磷酸腺苷产量增加两倍。血管活性肠肽是腺苷酸环化酶活性最有效的刺激剂，表明该肽在肠上皮细胞功能的环磷酸腺苷依赖性调节中具有重要的生理作用。
