The reaction mechanism of the Ga(III)Zn(II) derivative of uteroferrin and corresponding biomimetics.
Purple acid phosphatase from pig uterine fluid (uteroferrin), a representative of the diverse family of binuclear metallohydrolases, requires a heterovalent Fe(III)Fe(II) center for catalytic activity. The active-site structure and reaction mechanism of this enzyme were probed with a combination of methods including metal ion replacement and biomimetic studies. Specifically, the asymmetric ligand 2-bis{[(2-pyridylmethyl)-aminomethyl]-6-[(2-hydroxybenzyl)(2-pyridylmethyl)]aminomethyl}-4-methylphenol and two symmetric analogues that contain the softer and harder sites of the asymmetric unit were employed to assess the site selectivity of the trivalent and divalent metal ions using (71)Ga NMR, mass spectrometry and X-ray crystallography. An exclusive preference of the harder site of the asymmetric ligand for the trivalent metal ion was observed. Comparison of the reactivities of the biomimetics with Ga(III)Zn(II) and Fe(III)Zn(II) centers indicates a higher turnover for the former, suggesting that the M(III)-bound hydroxide acts as the reaction-initiating nucleophile. Catalytically active Ga(III)Zn(II) and Fe(III)Zn(II) derivatives were also generated in the active site of uteroferrin. As in the case of the biomimetics, the Ga(III) derivative has increased reactivity, and a comparison of the pH dependence of the catalytic parameters of native uteroferrin and its metal ion derivatives supports a flexible mechanistic strategy whereby both the mu-(hydr)oxide and the terminal M(III)-bound hydroxide can act as nucleophiles, depending on the metal ion composition, the geometry of the second coordination sphere and the substrate.
Smith
Sarah J
SJ
School of Molecular and Microbial Sciences, The University of Queensland, St Lucia, QLD, Australia.
Casellato
Annelise
A
Hadler
Kieran S
KS
Mitić
Natasa
N
Riley
Mark J
MJ
Bortoluzzi
Adailton J
AJ
Szpoganicz
Bruno
B
Schenk
Gerhard
G
Neves
Ademir
A
Gahan
Lawrence R
LR
D000135:Acid Phosphatase / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D040761:Biomimetic Materials / Q000737:chemistry*; D002384:Catalysis; D018360:Crystallography, X-Ray; D032061:Galium / Q000737:chemistry*; D007527:Isoenzymes / Q000737:chemistry*; D008024:Ligands; D019906:Nuclear Magnetic Resonance, Biomolecular; D010636:Phenols / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D013552:Swine; D000071681:Tartrate-Resistant Acid Phosphatase; D015032:Zinc / Q000737:chemistry*
C525240:2-bis(((2-pyridylmethyl)-aminomethyl)-6-((2-hydroxybenzyl)(2-pyridylmethyl))aminomethyl)-4-methylphenol; D007527:Isoenzymes; D008024:Ligands; D010636:Phenols; D011725:Pyridines; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D015032:Zinc
Biochem Biophys Res Commun. 1978 May 30;82(2):615-20
666864
Acta Crystallogr D Biol Crystallogr. 2004 Feb;60(Pt 2):298-303
14747706
J Am Chem Soc. 2002 Mar 20;124(11):2595-603
11890810
FEBS J. 2005 Jun;272(12):2968-77
15955057
Biochemistry. 1987 Jun 2;26(11):3115-20
3607015
J Inorg Biochem. 2003 Dec 1;97(4):315-23
14568235
Inorg Chem. 2002 Nov 4;41(22):5787-94
12401084
Gene. 2000 May 30;250(1-2):117-25
10854785
J Mol Biol. 1996 Jun 21;259(4):737-48
8683579
J Biol Chem. 1983 Mar 10;258(5):3166-72
6298226
Inorg Chem. 2002 Nov 4;41(22):5641-3
12401063
Structure. 1999 Jul 15;7(7):757-67
10425678
J Biol Chem. 1988 Oct 25;263(30):15561-7
2844817
Biochemistry. 1999 Aug 3;38(31):9926-36
10433699
Biochemistry. 1991 Aug 20;30(33):8187-94
1868093
J Am Chem Soc. 2007 Jun 20;129(24):7486-7
17518469
Biochemistry. 1999 Aug 3;38(31):9914-25
10433698
Science. 1995 Jun 9;268(5216):1489-92
7770774
Chem Rev. 2006 Aug;106(8):3338-63
16895331
Arch Biochem Biophys. 2005 Jul 15;439(2):154-64
15950921
Biochemistry. 2004 Aug 17;43(32):10387-92
15301537
J Synchrotron Radiat. 2005 Jul;12(Pt 4):537-41
15968136
Biochemistry. 1998 May 26;37(21):7813-21
9601042
Arch Biochem Biophys. 2004 Apr 15;424(2):154-62
15047187
J Biol Inorg Chem. 2005 Jun;10(4):319-32
15843985
Eur J Biochem. 1999 Mar;260(3):709-16
10102999
J Am Chem Soc. 2007 Aug 8;129(31):9550-1
17636903
Biochemistry. 1998 Jun 9;37(23):8490-7
9622501
J Biol Chem. 2001 Jun 1;276(22):19084-8
11278566
J Am Chem Soc. 2002 Nov 27;124(47):13974-5
12440878
Biochemistry. 1996 Nov 5;35(44):13946-54
8909292
Bone. 2000 Nov;27(5):575-84
11062342
J Mol Biol. 2005 Aug 5;351(1):233-46
15993892
Inorg Chem. 2000 Aug, 7;39(16):3526-36
11196811
J Biol Inorg Chem. 2005 Aug;10(5):550-63
16096803
J Mol Biol. 1999 Aug 6;291(1):135-47
10438611
Proc Natl Acad Sci U S A. 2005 Jan 11;102(2):273-8
15625111
Biochim Biophys Acta. 1984 Dec 21;791(3):357-63
6518164
Inorg Chem. 2002 Sep 9;41(18):4624-6
12206683
Acta Crystallogr D Biol Crystallogr. 1999 Dec;55(Pt 12):2051-2
10666589
Arch Biochem Biophys. 1999 Oct 15;370(2):183-9
10510276
J Am Chem Soc. 2001 Aug 15;123(32):7935-6
11493079