Khanna A K, Nomura Y, Fischetti V A, Zabriskie J B
Rockefeller University, New York, NY 10021, USA.
J Autoimmun. 1997 Feb;10(1):99-106. doi: 10.1006/jaut.1996.0107.
Previous work from this laboratory has demonstrated the occurrence of heart reactive antibodies (HRA) in the sera of acute rheumatic fever (ARF) patients which bound primarily to the sarcolemmal sheath of cardiac myofibres. While many investigators have reported the presence of antibodies to myosin in the sera of ARF patients, the question of whether these sera also contain antibodies to other cytoskeletal proteins has not been addressed. In this study, crude human sarcolemmal sheaths were extracted with 3 M KCl and partially purified using a DEAE cellulose column and a step gradient of NaCl. Maximum reactivity with ARF sera was seen with a protein fraction eluted with 0.3 M NaCl. Using FPLC, a single polypeptide of 38 kDa reacted in ELISA preferentially with ARF sera when compared to sera from patients with uncomplicated streptococcal infections and acute post-streptococcal glomerulonephritis (APSGN). A comparison of the N-terminal sequence of the purified protein and competitive inhibition assays indicated that the reactive sarcolemmal antigen was human cardiac tropomyosin.
该实验室之前的研究表明，急性风湿热（ARF）患者血清中存在心脏反应性抗体（HRA），这些抗体主要与心肌纤维的肌膜鞘结合。虽然许多研究者报告了ARF患者血清中存在抗肌球蛋白抗体，但这些血清是否还含有针对其他细胞骨架蛋白的抗体这一问题尚未得到解决。在本研究中，用3M KCl提取粗制的人肌膜鞘，并使用DEAE纤维素柱和NaCl梯度进行部分纯化。用0.3M NaCl洗脱的蛋白组分与ARF血清的反应性最强。使用快速蛋白质液相色谱（FPLC），与单纯链球菌感染患者和急性链球菌感染后肾小球肾炎（APSGN）患者的血清相比，一种38kDa的单一多肽在酶联免疫吸附测定（ELISA）中优先与ARF血清发生反应。纯化蛋白的N端序列比较和竞争性抑制试验表明，反应性肌膜抗原是人心肌肌钙蛋白。
