Semisynthetic cytochrome c.

Abstract

Horse heart cytochrome c can be split with cyanogen bromide into a heme peptide (residues 1-65) and a nonheme peptide (residues 66-104). In a process involving (i) complex formation between the two fragments and (ii) restoration of the severed peptide linkage, a fully active cytochrome c preparation can be re-formed. Use has been made of this process to couple the heme peptide to peptide 66-104 synthesized by the Merrifield solid-phase procedure. The semisynthetic product formed in this manner is indistinguishable from reconstituted cytochrome c prepared with nonsynthetic peptide 66-104.

Structural studies of the heme domain of sulfite oxidase: cyanogen bromide fragments

“…Mixture of the two peptides generated by digestion of horse heart cytochrome c with cyanogen bromide results in a 1:1 complex with properties resembling the native protein (Corradin & Harbury, 1971). Recently, it was demonstrated that the two CNBr peptides of cytochrome c can reform the severed polypeptide linkage resulting in a fully active protein with only homoserine replacing the methionine (Barstow et al, 1977).…”

The semisynthesis of fragments corresponding to residues 66-104 of horse heart cytochrome c

“…The present paper describes the application of the semisynthetic method to the production of a fragment, and some of its analogues, corresponding to residues 66-104 (which we will call fragment BC). Fragment BC or its analogues can be recombined via a peptide bond with fragment A either by the spontaneous aminolysis of the C-terminal homoserine lactone of the latter (Corradin & Harbury, 1974; Barstow et al, 1977;Boon et al, 1978), or by more conventional methods of peptide coupling (Wallace, 1976).…”