Alkylamine-ligated H93G myoglobin cavity mutant: a model system for endogenous lysine and terminal amine ligation in heme proteins such as nitrite reductase and cytochrome f.
His93Gly sperm whale myoglobin (H93G Mb) has the proximal histidine ligand removed to create a cavity for exogenous ligand binding, providing a remarkably versatile template for the preparation of model heme complexes. The investigation of model heme adducts is an important way to probe the relationship between coordination structure and catalytic function in heme enzymes. In this study, we have successfully generated and spectroscopically characterized the H93G Mb cavity mutant ligated with less common alkylamine ligands (models for Lys or the amine group of N-terminal amino acids) in numerous heme iron states. All complexes have been characterized by electronic absorption and magnetic circular dichroism spectroscopy in comparison with data for parallel imidazole-ligated H93G heme iron moieties. This is the first systematic spectral study of models for alkylamine- or terminal amine-ligated heme centers in proteins. High-spin mono- and low-spin bis-amine-ligated ferrous and ferric H93G Mb adducts have been prepared together with mixed-ligand ferric heme complexes with alkylamine trans to nitrite or imidazole as heme coordination models for cytochrome c nitrite reductase or cytochrome f, respectively. Six-coordinate ferrous H93G Mb derivatives with CO, NO, and O(2) trans to the alkylamine have also been successfully formed, the latter for the first time. Finally, a novel high-valent ferryl species has been generated. The data in this study represent the first thorough investigation of the spectroscopic properties of alkylamine-ligated heme iron systems as models for naturally occurring heme proteins ligated by Lys or terminal amines.
Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 20208, United States.
Jing
J
Du
Roshan
R
Perera
John H
JH
Dawson
D000478:Alkylation; D000588:Amines / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D002384:Catalysis; D002942:Circular Dichroism; D045348:Cytochromes f / Q000378:metabolism*; D005998:Glycine / Q000235:genetics / Q000378:metabolism; D006639:Histidine / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D008239:Lysine / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D009211:Myoglobin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009572:Nitrite Reductases / Q000378:metabolism*; D013059:Spectrum Analysis, Raman; D050661:Sperm Whale / Q000235:genetics / Q000378:metabolism
D000588:Amines; D008024:Ligands; D009211:Myoglobin; D006639:Histidine; D045348:Cytochromes f; D009572:Nitrite Reductases; D008239:Lysine; D005998:Glycine
Nat New Biol. 1971 Sep 1;233(35):15-6
5286220
Biochemistry. 2010 May 25;49(20):4327-38
20411915
Biochem Biophys Res Commun. 1996 Nov 21;228(3):752-6
8941349
J Biol Chem. 1982 May 25;257(10):5496-502
6279603
Biochemistry. 2002 Mar 5;41(9):2921-31
11863430
Biochemistry. 1994 May 31;33(21):6546-54
8204590
Biochemistry. 2005 Oct 4;44(39):13179-91
16185086
J Inorg Biochem. 2006 May;100(5-6):1100-8
16603247
Inorg Chem. 2000 Dec 25;39(26):6061-6
11151505
J Am Chem Soc. 1976 Oct 27;98(22):6970-5
965659
Dalton Trans. 2007 Oct 21;(39):4371-85
17909648
Biochemistry. 2006 Mar 14;45(10):3170-7
16519512
Biochemistry. 2000 Jul 4;39(26):7689-701
10869174
J Biol Chem. 2000 Dec 15;275(50):39608-16
10984487
J Inorg Biochem. 2010 Mar;104(3):357-64
20110129
Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):3641-6
12655049
DNA Cell Biol. 2002 Apr;21(4):271-80
12042067
Science. 1988 Apr 22;240(4851):433-9
3358128
J Biol Inorg Chem. 1999 Feb;4(1):64-72
10499104
Nature. 1999 Jul 29;400(6743):476-80
10440380
Biochim Biophys Acta. 1959 Oct;35:543
13837237
Nat Struct Biol. 2000 Oct;7(10):876-80
11017196
J Biol Chem. 1972 Apr 25;247(8):2447-55
4336375
J Am Chem Soc. 1972 Mar 22;94(6):2073-8
4335729
J Inorg Biochem. 2006 Aug;100(8):1413-25
16777231
J Photochem Photobiol B. 2004 May 27;74(2-3):135-43
15157909
J Biol Chem. 1960 Dec;235:3646-53
13711454
J Am Chem Soc. 2002 Oct 2;124(39):11737-45
12296741
J Am Chem Soc. 1976 May 12;98(10):3014-5
1262630