A protein comprising amino acid sequence of SEQ ID NO: 115, within which a segment of general formula Ih-mod GX.sub.1CX.sub.1VX.sub.2X.sub.3X.sub.4X.sub.5 is present where X.sub.1 is any of F, Y, L, P, Q, M, V, W, A, or T, X.sub.1V is R, or K, X.sub.2 is any of A, G, S, or T, X.sub.3 is any amino acid of the 17-set, where the 17-set comprises A, I, L, F, or Y, X.sub.4 is any of K, I, Q, R, H, S, F, M, N, L, or V, and X.sub.5 is any of R, V, I, K, M, Q, E, F, L, N, Y, D, S, H; and b) in position 34 of SEQ ID NO: 115 it contains an amino acid selected from the 34-set contains any amino acid of the 34-set, where the 34-set comprises Y, I, F, G, V and S, and use in pharmaceutical preparations, kits, screening procedures.