Carter W A
Proc Natl Acad Sci U S A. 1970 Oct;67(2):620-8. doi: 10.1073/pnas.67.2.620.
During the purification of mouse and human interferons, multiple active components have been detected. Mouse interferon was purified over 500-fold by differential precipitation, centrifugation, gel chromatography, and isoelectric focusing. On electrofocusing, two molecular forms (A and B) were noted. Form B (isoelectric point 7.35) had a molecular weight of about 38,000 and Form A (isoelectric point 7.15), which was equally active, a molecular weight of 19,000. Purified Form B was dissociable into Form A, but the reverse reaction occurred to a much lesser extent. Human interferon, purified about 1550-fold, is also composed of multiple molecular forms. Form B (pI 5.60) had a molecular weight of about 24,000 and Form A (pI 5.35), which may contain up to 85% of the total activity, a molecular weight of 12,000. Both forms appear to be equally active. The dissociation of both human and mouse interferons into subunits appears to take place during dialysis versus low salt (0.01 M Tris pH 7.4). The data are consistent with the idea that the native molecule exists as a dimer of similar or identical subunits. Dimer formation, which probably occurs within the cells, does not seem to lead to a measurable cooperative effect between the subunits.
在小鼠和人干扰素的纯化过程中，检测到了多种活性成分。通过分级沉淀、离心、凝胶色谱和等电聚焦等方法，小鼠干扰素的纯化倍数超过了500倍。在等电聚焦时，发现了两种分子形式（A和B）。B型（等电点7.35）的分子量约为38,000，A型（等电点7.15）的活性与之相当，分子量为19,000。纯化后的B型可解离为A型，但逆反应的程度要小得多。纯化倍数约为1550倍的人干扰素也由多种分子形式组成。B型（pI 5.60）的分子量约为24,000，A型（pI 5.35）的分子量为12,000，其活性可能占总活性的85%。两种形式的活性似乎相当。人和小鼠干扰素解离为亚基的过程似乎发生在与低盐（0.01 M Tris pH 7.4）透析期间。这些数据与天然分子以相似或相同亚基的二聚体形式存在的观点一致。二聚体的形成可能发生在细胞内，似乎不会导致亚基之间产生可测量的协同效应。
