Brewer H B, Fairwell T, Kay L, Meng M, Ronan R, Law S, Light J A
Biochem Biophys Res Commun. 1983 Jun 15;113(2):626-32. doi: 10.1016/0006-291x(83)91772-2.
Human apoA-I is synthesized as preproapoA-I, a 267 amino acid precursor apolipoprotein. PreproapoA-I initially undergoes intracellular co-translational proteolytic cleavage into proapoA-I. ProapoA-I is secreted from the cell and was isolated from thoracic duct lymph in the apoA-I1 isoform position. The amino-terminal sequence of proapoA-I isolated from human lymph revealed the presence of 6 additional amino acids, Arg-His-Phe-Trp-Gln-Gln, on the amino-terminal end of apoA-I consistent with the proapoA-I sequence determined by nucleic acid sequence analysis of cloned apoA-I. Our results indicate that proapoA-I is present in human plasma, and undergoes post-translational proteolytic cleavage to mature plasma apoA-I.
人载脂蛋白A-I最初作为前体载脂蛋白A-I合成，它是一种含有267个氨基酸的前体载脂蛋白。前体载脂蛋白A-I最初在细胞内经历共翻译蛋白水解切割，形成载脂蛋白A-I原。载脂蛋白A-I原从细胞中分泌出来，并在载脂蛋白A-I1异构体位置从胸导管淋巴中分离出来。从人淋巴中分离出的载脂蛋白A-I原的氨基末端序列显示，在载脂蛋白A-I的氨基末端存在另外6个氨基酸，即精氨酸-组氨酸-苯丙氨酸-色氨酸-谷氨酰胺-谷氨酰胺，这与通过克隆的载脂蛋白A-I的核酸序列分析确定的载脂蛋白A-I原序列一致。我们的结果表明，载脂蛋白A-I原存在于人体血浆中，并经历翻译后蛋白水解切割，形成成熟的血浆载脂蛋白A-I。
