... site for thecatalytic tetramer C1r2–C1s2, essential for the C1 activity[35]. Our results show that C1q as well as C1 bind to DNA,and that C1r can bind to C1q bound to DNA. Thus DNAbinding ... reconstitution of C1 from C1r, C1s, and C1q [14]. Thus, unlike DNA, fucoidanalso interacts with the Ôarms domainÕ of CLR, whichcontains the binding site of the tetramer C1r2–C1s2.Ithasbeen ... beenproposed as a potential physiologic C1q inhibitor, throughthe inhibition of the C1q– (C1r2–C1s2) assembly [37].Other C1q binding substances that are not C1q inhibi-tors, like DNA, C-reactive...