Záková Lenka, Kazdová Ludmila, Hanclová Ivona, Protivínská Eva, Sanda Miloslav, Budesínský Milos, Jirácek Jirí
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Praha 6, Czech Republic.
Biochemistry. 2008 May 27;47(21):5858-68. doi: 10.1021/bi702086w. Epub 2008 May 2.
In this study, we prepared several shortened and full-length insulin analogues with substitutions at position B26. We compared the binding affinities of the analogues for rat adipose membranes with their ability to lower the plasma glucose level in nondiabetic Wistar rats in vivo after subcutaneous administration, and also with their ability to stimulate lipogenesis in vitro. We found that [NMeHisB26]-DTI-NH 2 and [NMeAlaB26]-DTI-NH 2 were very potent insulin analogues with respect to their binding affinities (214 and 465%, respectively, compared to that of human insulin), but they were significantly less potent than human insulin in vivo. Their full-length counterparts, [NMeHisB26]-insulin and [NMeAlaB26]-insulin, were less effective than human insulin with respect to binding affinity (10 and 21%, respectively) and in vivo activity, while [HisB26]-insulin exhibited properties similar to those of human insulin in all of the tests we carried out. The ability of selected analogues to stimulate lipogenesis in adipocytes was correlated with their biological potency in vivo. Taken together, our data suggest that the B26 residue and residues B26-B30 have ambiguous roles in binding affinity and in vivo activity. We hypothesize that our shortened analogues, [NMeHisB26]-DTI-NH 2 and [NMeAlaB26]-DTI-NH 2, have different modes of interaction with the insulin receptor compared with natural insulin and that these different modes of interaction result in a less effective metabolic response of the insulin receptor, despite the high binding potency of these analogues.
在本研究中,我们制备了几种在B26位有取代的缩短型和全长胰岛素类似物。我们比较了这些类似物与大鼠脂肪细胞膜的结合亲和力,以及它们在皮下给药后降低非糖尿病Wistar大鼠体内血糖水平的能力,还比较了它们在体外刺激脂肪生成的能力。我们发现,[NMeHisB26]-DTI-NH₂和[NMeAlaB26]-DTI-NH₂在结合亲和力方面是非常有效的胰岛素类似物(分别是人类胰岛素的214%和465%),但它们在体内的效力明显低于人类胰岛素。它们的全长对应物,[NMeHisB26]-胰岛素和[NMeAlaB26]-胰岛素,在结合亲和力(分别为10%和21%)和体内活性方面比人类胰岛素效果更差,而[HisB26]-胰岛素在我们进行的所有测试中表现出与人类胰岛素相似的特性。所选类似物刺激脂肪细胞脂肪生成的能力与其在体内的生物学效力相关。综上所述,我们的数据表明,B26残基以及B26 - B30残基在结合亲和力和体内活性方面具有不明确的作用。我们推测,我们的缩短型类似物,[NMeHisB26]-DTI-NH₂和[NMeAlaB26]-DTI-NH₂,与天然胰岛素相比,与胰岛素受体有不同的相互作用模式,并且尽管这些类似物具有高结合效力,但这些不同的相互作用模式导致胰岛素受体的代谢反应效率较低。