Peake P W, Pussell B A, Karplus T E, Riley E H, Charlesworth J A
Department of Nephrology, Prince Henry Hospital, Little Bay, NSW, Australia.
APMIS. 1991 May;99(5):460-6. doi: 10.1111/j.1699-0463.1991.tb05176.x.
Nephritis strain-associated protein (NSAP), a streptokinase produced by strains of streptococci isolated from patients with acute glomerulonephritis, is believed to be a specific antigen which participates in the production of glomerular injury. In order to investigate the mechanisms by which NSAP induces damage we have examined its potential to activate complement in vitro and to bind to isolated human glomeruli. NSAP, both alone and in combination with specific antibody, caused depletion of complement in normal human serum as measured by total haemolytic complement activity and generation of the complement breakdown products. C3a and C4a. Furthermore, Scatchard analysis showed that NSAP bound tightly to human glomeruli (Ka of 400 +/- 240 x 10(6) M) when compared to non-nephritic streptokinase (Ka of 7.3 +/- 4.1 x 10(6) M) and fully cationized human serum albumin (Ka of 0.6 +/- 0.04 x 10(6) M). These findings are consistent with the hypothesis that the deposition of streptococcal antigens within the glomerulus may precede the fixation of complement and specific antibody.
肾炎菌株相关蛋白（NSAP）是从急性肾小球肾炎患者中分离出的链球菌菌株产生的一种链激酶，被认为是一种参与肾小球损伤产生的特异性抗原。为了研究NSAP诱导损伤的机制，我们检测了其在体外激活补体以及与分离出的人肾小球结合的潜力。通过总溶血补体活性和补体裂解产物C3a和C4a的生成来测定，NSAP单独以及与特异性抗体联合使用时，均可导致正常人血清中的补体耗竭。此外，Scatchard分析表明，与非肾炎性链激酶（Ka为7.3±4.1×10⁶ M）和完全阳离子化的人血清白蛋白（Ka为0.6±0.04×10⁶ M）相比，NSAP与人肾小球紧密结合（Ka为400±240×10⁶ M）。这些发现与以下假设一致，即肾小球内链球菌抗原的沉积可能先于补体和特异性抗体的固定。
