Synthesis and characterization of singly modified (carboxyferrocenyl)cytochrome c derivatives.
Carbodiimide-activated coupling chemistry has been used to covalently attach 1,1'-dicarboxyferrocene (dcFc) to the epsilon-amine of surface lysine residues of horse heart cytochrome c. Conditions have been found that optimize the production of singly modified (dcFc)cytochrome c derivatives and the presence of one free carboxylate per modification site allows separation and purification of about 10 of these derivatives by cation-exchange chromatography. Reversed-phase HPLC tryptic peptide mapping techniques have been used to identify the attachment sites of eight pure (dcFc)cytochrome c derivatives (at lysines 7, 8, 13, 25, 60, 72, 73, and 100). Through-space distances from these lysines to the nearest heme edge span the 6-16 A range and these derivatives should prove useful in exploring the distance dependence of long-range intramolecular electron transfer in cytochrome c.
Gorren
A C
AC
Department of Chemistry, University of Georgia, Athens 30602.
Chan
M L
ML
Crouse
B R
BR
Scott
R A
RA
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003574:Cytochrome c Group / Q000737:chemistry*; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D006736:Horses; D006863:Hydrogen-Ion Concentration; D009206:Myocardium / Q000201:enzymology; D010449:Peptide Mapping; D013056:Spectrophotometry, Ultraviolet; D014357:Trypsin
D003574:Cytochrome c Group; D005296:Ferrous Compounds; D014357:Trypsin