Yu Rongjie, Yi Tianhong, Zhang Ling, Hong An, Dai Yun, Zhou Tianhong
Bio-engineering Institute of Jinan University, Jinan University, Guangzhou, China.
Acta Biochim Biophys Sin (Shanghai). 2008 Dec;40(12):1015-22. doi: 10.1111/j.1745-7270.2008.00485.x.
Maxadilan is a potent vasodilatory peptide present in the salivary glands of the sand fly. Maxadilan and M65, a deletion variation of maxadilan, are agonist- and antagonist-specific for the PAC1 receptor. In order to obtain the recombinant maxadilan and M65 efficiently by intein-mediated single column purification, the genes encoding maxadilan and M65 were designed, synthesized and cloned into Escherichia coli expression vector pKYB. The recombinant maxadilan and M65 with homogeneity over 95% were released from the chitin-bound intein tag by beta-mercaptoethanol. Intraperitoneal injection of the recombinant maxadilan caused an acute elevation of plasma glucose, imitating pituitary adenylate cyclase-activating polypeptide (PACAP) 27, in NIH mice, while the VPAC1-agonist and VPAC2-agonist had no significant effects on the levels of plasma glucose. M65 alone had no effect on the plasma glucose, but blocked the glucose excursion caused by maxadilan by 12.7% and blocked the glucose excursion caused by the PACAP 27 by 11.6%. The acute effects of the recombinant maxadilan and M65 on the plasma glucose indicated that they had the characteristics as the agonist and antagonist for PAC1.
麦克斯迪兰是一种存在于沙蝇唾液腺中的强效血管舒张肽。麦克斯迪兰和M65（麦克斯迪兰的一种缺失变体）分别是PAC1受体的激动剂和拮抗剂。为了通过内含肽介导的单柱纯化高效获得重组麦克斯迪兰和M65，设计、合成了编码麦克斯迪兰和M65的基因，并将其克隆到大肠杆菌表达载体pKYB中。通过β-巯基乙醇从几丁质结合的内含肽标签上释放出纯度超过95%的重组麦克斯迪兰和M65。腹腔注射重组麦克斯迪兰会使NIH小鼠的血糖急性升高，类似于垂体腺苷酸环化酶激活多肽（PACAP）27的作用，而VPAC1激动剂和VPAC2激动剂对血糖水平无显著影响。单独使用M65对血糖无影响，但可使麦克斯迪兰引起的血糖波动降低12.7%，使PACAP 27引起的血糖波动降低11.6%。重组麦克斯迪兰和M65对血糖的急性作用表明它们具有作为PAC1激动剂和拮抗剂的特性。
