Dysfunctional C1-inhibitor(At), isolated from a type II hereditary-angio-oedema plasma, contains a P1 ‘reactive centre’ (Arg444→His) mutation

Simple rapid procedures for identification and analysis of dysfunctional C1-inhibitor proteins mutated at the reactive-centre P1 residue have been developed and used to define structurally a C1-inhibitor protein, C1-inhibitor(At), isolated from an individual with hereditary angio-oedema. The observed mutation, Arg444----His, is compatible with a single base change in the codon used for Arg444 in the native protein.