Catalytic properties and bioluminescence spectra of firefly Luciola mingrelica wiht point mutations exterior to the active site

摘要

Mutant forms of recombinant luciferase of firefly Luciola mingrelica with His433Asn and His433Ser point replaements were obtained by the method of site-directed mutagenesis.Physicochemical properties of the initial recombinant firefly luciferase adn its mutants were studied.It was shown tht for Luciola mingrelica luciferase and its mutant forms,the K_m,LH_2 values conicided.The replaement of His433Asn led to the grwoth of K_m,ATP by 20% and to the lowering of the specific acitvity by 20%;the replacement of His433Ser led to an increase in K_m,ATP by 50% and lowered the specific activity to 1/200 of the initial alue.A model of the influence of the replacements of His433 residue by the active site of luciferase of Luciola mingrelica firefly is proposed.