Fig. 3. Plasmon resonance analysis of K8/K18 binding. (A) Binding of 20 µg/ml K8 (wild type), K8(G62C), K8(I63V), K8(K464N) or BSA to immobilized wild-type recombinant K18 protein for 5 minutes, followed by washing for 5 minutes, under reducing conditions. K8(G62C) and K8(K464N) binding was less efficient than K8 (wild type), and K8(I63V) was similar to wild type. (B) Binding of K18(S230T) to wild-type immobilized K8 was impaired compared with K18 (wild type), and BSA binding was negligible. Once formed, all K8-K18 interactions were stable as shown by the persistent plateau through the wash period.