Regioselective cleavage of myoglobin with copper(II) compounds at neutral pH.
Selective hydrolytic cleavage of myoglobin was studied with CuCl2, Cu(ClO4)2, Cu(AC)2, and binuclear Cu(II) complexes of 3,6,9,16,19,22-hexaaza-6,19-bis (2-hydroxyethyl)-tricyclo- [22,2,2,2(11,14)]-triaconta-1,11,13,24,27,29-hexaene (1) and 3,6,9,16,19,22-hexaaza-tricyclo-[22,2,2,2(11,14)]-triaconta- 1,11,13,24,27,29-hexaene (2). The sites of cleavage were precisely determined by LC-ESIMS and further confirmed by an MS/MS method through fragmentation from both the N-terminal and C-terminal. The peptide bonds of Gln91-Ser92 and Ala94-Thr95 were remarkably cleaved by Cu(II) anchored to the side chain of the His93 residue. The data presented in this study show that Cu(II)-mediated cleavage of myoglobin is able to proceed at neutral pH, more selectively than Pd(II)-mediated cleavage, and buffer solution of phosphate and NH4HCO3 accelerates the cleavage reaction.
Zhang
Lin
L
State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Nanjing University, Nanjing, 210093, China.
Mei
Yuhua
Y
Zhang
Yu
Y
Li
Shuan
S
Sun
Xiaojuan
X
Zhu
Longgen
L
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002384:Catalysis; D003300:Copper / Q000737:chemistry / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D006321:Heart; D006736:Horses; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013058:Mass Spectrometry; D015394:Molecular Structure; D009211:Myoglobin / Q000737:chemistry* / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D000596:Amino Acids; D009211:Myoglobin; D010455:Peptides; D003300:Copper