Fontaine M, Rivat C
Ann Immunol (Paris). 1979 May-Jun;130C(3):349-66.
This paper reports the description of fragments of human C3, purified from aged sera. Sera were incubated at different temperatures (4 degrees, 20 degrees and 37 degrees C) for 8 days or more. At 4 degrees C, the major isolated fragment was C3b which showed a heterogeneity of structure. Under reducing conditions, it liberated a 40,000 dalton fragment which reacted against an anti-C3d and which we called "C3d-like". At 20 degrees C, C3b was partially destroyed to yield the C3c- and C3d-fragments. At 37 degrees C, C3d and C3c were obtained. C3c presented a structural heterogeneity. It was made either of two chains of 75,000 daltons or of three chains with 75,000, 38,000 and 31,000 dalton MW. The comparison of these fragments with those obtained by tryptic hydrolysis led us to propose a pathway to the degradation of C3 and to bring some informations about the structure of this molecule.
本文报道了从老化血清中纯化得到的人C3片段的描述。血清在不同温度（4℃、20℃和37℃）下孵育8天或更长时间。在4℃时，主要分离出的片段是C3b，其结构具有异质性。在还原条件下，它释放出一个40,000道尔顿的片段，该片段与抗C3d反应，我们称之为“C3d样”片段。在20℃时，C3b被部分破坏，产生C3c和C3d片段。在37℃时，得到C3d和C3c。C3c呈现出结构异质性。它由两条75,000道尔顿的链组成，或者由三条分子量分别为75,000、38,000和31,000道尔顿的链组成。将这些片段与胰蛋白酶水解得到的片段进行比较，使我们提出了C3降解的途径，并提供了有关该分子结构的一些信息。
