A mass spectrometry method for mapping the interface topography of interacting proteins, illustrated by the melittin-calmodulin system.
The shielding of lysine groups from acetylation by acetic anhydride has been used to identify the regions of calmodulin in contact with melittin in the 1:1 complex. The estimation of the degree of acetylation was done by examining cyanogen bromide and cyanogen bromide/trypsin digests by mass spectrometry. Evidence was obtained that lysines-21, -75, and -148 are protected to some extent, with the implication that both the N- and C-terminal lobes and the connecting strand are involved in the interaction.
Steiner
R F
RF
Department of Chemistry and Biochemistry, University of Maryland (Baltimore County) 21228.
Albaugh
S
S
Fenselau
C
C
Murphy
C
C
Vestling
M
M
D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D002147:Calmodulin / Q000737:chemistry*; D002417:Cattle; D003488:Cyanogen Bromide; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008555:Melitten / Q000737:chemistry*; D008969:Molecular Sequence Data; D010449:Peptide Mapping / Q000379:methods*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013917:Thrombin; D014908:Triticum; D014357:Trypsin
D002147:Calmodulin; D008555:Melitten; D014357:Trypsin; D013917:Thrombin; D003488:Cyanogen Bromide