Guillen A, Haro A, Gavilanes F G, Municio A M
Department of Biochemistry, Faculty of Chemistry, Universidad Complutense, Madrid, Spain.
Arch Biochem Biophys. 1991 May 1;286(2):591-5. doi: 10.1016/0003-9861(91)90085-w.
Adenylate cyclase activation by GTP and octopamine as well as basal activity (in the presence of Mg2+) have been studied as a function of membrane structure in plasma membranes from brain of the dipterous Ceratitis capitata. Benzyl alcohol and lidocaine, but not phenobarbital, inhibited the three activities to the same extent. Triton X-100-solubilized adenylate cyclase was also inhibited by benzyl alcohol and lidocaine, but not by phenobarbital. Results could be explained by an effect on the catalytic unit lipid environment, which would be maintained after solubilization, counteracting the effect of these drugs to facilitate lateral diffusion and coupling of adenylate cyclase components in the lipid bilayer. The observation that the insect adenylate cyclase is relatively insensitive to changes in bulk bilayer fluidity is strengthened by the absence of effect of phenobarbital on enzyme activities. Indeed, this compound was as active as lidocaine or benzyl alcohol in increasing bulk membrane fluidity. The response of C. capitata adenylate cyclase to changes in membrane fluidity is different from that recorded in mammalian systems. This may be functionally important and result from the fact that insects are not warm-blooded.
已经研究了在双翅目地中海实蝇大脑质膜中，GTP和章鱼胺对腺苷酸环化酶的激活作用以及基础活性（在Mg2+存在下）与膜结构的关系。苯甲醇和利多卡因而非苯巴比妥，同等程度地抑制了这三种活性。Triton X-100增溶的腺苷酸环化酶也受到苯甲醇和利多卡因的抑制，但不受苯巴比妥的抑制。结果可以通过对催化单位脂质环境的影响来解释，这种环境在增溶后仍会保持，抵消了这些药物促进脂质双层中腺苷酸环化酶成分侧向扩散和偶联的作用。苯巴比妥对酶活性无影响，这一观察结果进一步证明了昆虫腺苷酸环化酶对整体双层流动性变化相对不敏感。实际上，该化合物在增加整体膜流动性方面与利多卡因或苯甲醇一样有效。地中海实蝇腺苷酸环化酶对膜流动性变化的反应与在哺乳动物系统中记录的不同。这在功能上可能很重要，其原因在于昆虫不是温血动物。
