Milstein S J, Leipold H, Sarubbi D, Leone-Bay A, Mlynek G M, Robinson J R, Kasimova M, Freire E
Emisphere Technologies, Inc., Hawthorne, NY 10532, USA.
J Control Release. 1998 Apr 30;53(1-3):259-67. doi: 10.1016/s0168-3659(97)00259-9.
We have previously reported on the biological activity of members of a library of low molecular weight compounds (carriers) that enable the oral delivery of proteins (Milstein, Proceedings of the 1995 Miami Bio/Technology Winter Symposium on Protein Engineering and Structural Biology, IRL Press at Oxford University Press, 1995, p. 13; Leone-Bay et al., J. Med. Chem. 38 (1995) 4263-4269; Leone-Bay et al., J. Med. Chem. 39 (1996) 2571-2578; [1-3]). When rats or primates are orally administered a solution of carrier and either recombinant human alpha-interferon (rhIFN), insulin or recombinant human growth hormone (rhGH) significant serum concentrations of the proteins are detectable. The transport activity of these compounds is positively correlated with their structural effects on the protein molecules. Direct measurement of the interaction of these carrier molecules with the proteins indicates that they reversibly destabilize the native state of the molecule favoring a partially unfolded conformation. Apparently these intermediate protein conformations are transport competent and are able to be absorbed through the intestinal tissue and into the bloodstream. Since the measured binding of the carriers to the partially unfolded proteins is relatively weak (Kb = 100 M(-1)) and the systemic activity of the proteins appears to be unaffected, the changes in the structure of the proteins are manifestly reversible.
我们之前曾报道过一个低分子量化合物（载体）文库成员的生物活性，这些化合物能够实现蛋白质的口服递送（米尔斯坦，《1995年迈阿密蛋白质工程与结构生物学生物技术冬季研讨会论文集》，牛津大学出版社IRL出版社，1995年，第13页；莱昂 - 贝伊等人，《药物化学杂志》38 (1995) 4263 - 4269；莱昂 - 贝伊等人，《药物化学杂志》39 (1996) 2571 - 2578；[1 - 3]）。当给大鼠或灵长类动物口服载体与重组人α - 干扰素（rhIFN）、胰岛素或重组人生长激素（rhGH）的溶液时，可检测到蛋白质在血清中的显著浓度。这些化合物的转运活性与其对蛋白质分子的结构效应呈正相关。对这些载体分子与蛋白质相互作用的直接测量表明，它们可逆地破坏分子的天然状态，有利于部分展开的构象。显然，这些中间蛋白质构象具有转运能力，能够通过肠道组织吸收进入血液。由于测得的载体与部分展开蛋白质的结合相对较弱（Kb = 100 M(-1)），且蛋白质的全身活性似乎未受影响，蛋白质结构的变化显然是可逆的。
