Wu Y, Foreman R C
Department of Physiology and Pharmacology, University of Southampton, UK.
FEBS Lett. 1990 Jul 30;268(1):21-3. doi: 10.1016/0014-5793(90)80962-i.
A glutamic acid to lysine change in the Z variant of human alpha 1-antitrypsin is associated with a failure to secrete the protein from synthesising cells. The block in export of the protein may be caused either by the loss of an acidic residue or the introduction of a basic one at this point in the polypeptide chain. Site-directed mutagenesis has been used to construct novel alpha 1-antitrypsin mutants which show that the side chain interactions from Glu-342 are not obligatory for protein export and it is rather the introduction of a basic residue at this point which produces the intracellular accumulation of the protein.
人类α1-抗胰蛋白酶Z变体中谷氨酸到赖氨酸的变化与该蛋白无法从合成细胞中分泌出来有关。蛋白质输出受阻可能是由于酸性残基的丢失，或者是在多肽链的这一点上引入了一个碱性残基。定点诱变已被用于构建新型α1-抗胰蛋白酶突变体，这些突变体表明来自Glu-342的侧链相互作用对于蛋白质输出并非必不可少，而是在这一点上引入碱性残基导致了蛋白质在细胞内的积累。
