Spectroscopic and magnetic studies of the purple acid phosphatase from bovine spleen

Averill, Bruce A.; Davis, James C.; Burman, Sudhir; Zirino, Teresa; Sanders-Loehr, Joann; Loehr, Thomas M.; Sage, J. Timothy; Debrunner, Peter G.

doi:10.1021/ja00246a039

Cited by 170 publications

(180 citation statements)

References 8 publications

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“…The pK a of water coordinated to ferric ion in model complexes is $3 [26]. The assignment is consistent with spectroscopic studies of the interaction of phosphates with the bovine and pig enzymes [25,[27][28][29][30], which revealed an ionization occurring in the pH range 3.9-4.8. The conjugate base, a coordinated hydroxyl group, is a potential candidate for the attacking nucleophile in hydrolysis [25,[29][30][31].…”

Section: Resultssupporting

confidence: 76%

Phosphotyrosyl peptides and analogues as substrates and inhibitors of purple acid phosphatases

Valizadeh

Schenk

Nash

et al. 2004

Archives of Biochemistry and Biophysics

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Purple acid phosphatases are metal-containing hydrolases. While their precise biological role(s) is unknown, the mammalian enzyme has been linked in a variety of biological circumstances (e.g., osteoporosis) with increased bone resorption. Inhibition of the human enzyme is a possible strategy for the treatment of bone-resorptive diseases such as osteoporosis. Previously, we determined the crystal structure of pig purple acid phosphatase to 1.55 A and we showed that it is a good model for the human enzyme. Here, a study of the pH dependence of its kinetic parameters showed that the pig enzyme is most efficient at pH values similar to those encountered in the osteoclast resorptive space. Based on the observation that phosphotyrosine-containing peptides are good substrates for pig purple acid phosphatase, peptides containing a range of phosphotyrosine mimetics were synthesized. Kinetic analysis showed that they act as potent inhibitors of mammalian and plant purple acid phosphatases, with the best inhibitors exhibiting low micromolar inhibition constants at pH 3-5. These compounds are thus the most potent organic inhibitors yet reported for the purple acid phosphatases.

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Section: Resultssupporting

confidence: 76%

Phosphotyrosyl peptides and analogues as substrates and inhibitors of purple acid phosphatases

Valizadeh

Schenk

Nash

et al. 2004

Archives of Biochemistry and Biophysics

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“…The phosphatase-like activity promoted by the [Fe 4 (HPBA) 4 (l-CH 3 COO) 2 (l-OH)(l-O)(OH 2 ) 2 ]ClO 4 complex in 1:1 acetonitrile/water was measured using the substrate BDNPP. The complex dependence of the hydrolytic activity was measured at pH 6.5 with a BDNPP concentration of 5 mM.…”

Section: Phosphatase-like Kineticsmentioning

confidence: 99%

“…The enzyme isolated from mammals (pig, bovine, mouse, rat and human) is an approximately 35 kDa monomeric protein with an Fe(III)-Fe(II) centre, and a characteristic purple colour due to a charge-transfer transition (k max = 510-560 nm; e = *3,000-4,000 M -1 cm -1 ) from a conserved tyrosine ligand to the ferric ion ( Fig. 1) [3][4][5]. Mammalian PAPs are easily and reversibly oxidized to the inactive diferric form owing to the low redox potential (approximately 340 mV) of the divalent iron [6,7], suggesting that the PAP activity may be regulated in vivo by reversible oxidation/reduction of the active site.…”

Section: Introductionmentioning

confidence: 99%

Phosphate ester cleavage promoted by a tetrameric iron(III) complex

et al. 2010

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The purple acid phosphatases (PAPs) are the only binuclear metallohydrolases where the necessity for a heterovalent active site [Fe(III)-M(II) (M is Fe, Zn or Mn)] for catalysis has been established. The paradigm for the construction of PAP biomimetics, both structural and functional, is that the ligands possess characteristics which mimic those of the donor sites of the metalloenzyme and permit discrimination between trivalent and divalent metal ions. The donor atom set of the ligand 2-((2-hydroxy-5-methyl-3-((pyridin-2-ylmethylamino)methyl)benzyl) (2-hydroxybenzyl)amino)acetic acid (H 3 HPBA) mimics that of the active site of PAP although the iron(III) complex of this ligand has been characterized as the tetramer [Fe 4 (HPBA) 2 (l-CH 3 COO) 2 (l-O)(l-OH)(OH 2 ) 2 ]ClO 4 Á5H 2 O. The phosphoesterase-like activity of the complex in 1:1 acetonitrile/water has now been investigated using the substrate 2,4-bis(dinitrophenyl)phosphate. The pH dependence of the catalytic rate revealed a non-symmetric bellshaped profile, with a finite but non-zero rate at high pH. Unlike the traditional approach usually employed to analyse these bell-shaped profiles, the approach used here involved incorporating additional species which contribute to the overall activity. Employing this approach, we show that the complex has a k cat of 1.6 (±0.2) 9 10 -3 s -1 , three kinetically relevant pK a values of 5.3, 6.2 and 8.4, with K M of 7.4 ± 0.6 mM. The kinetic parameters are similar to those reported for heterovalent PAP biomimetics. Additionally, it is observed that, unlike the enzyme, the oxidation state is not the determining factor for catalytic activity.

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“…[4][5][6] Mammalian PAPs are $35 kDa monomeric proteins with a redox active Fe(III)-Fe(II/III) centre in their active sites. 7,8 While it is the reduced form that is catalytically active, only the structures of the inactive diferric forms of PAPs from human (hPAP) 9 and pig (pPAP) 10 have been determined by X-ray crystallography.…”

mentioning

confidence: 99%

Inhibition of purple acid phosphatase with α-alkoxynaphthylmethylphosphonic acids

McGeary

Vella

Mak

et al. 2009

Bioorganic & Medicinal Chemistry Letters

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a b s t r a c tPurple acid phosphatases (PAPs) are binuclear hydrolases that catalyse the hydrolysis of a range of phosphorylated substrates. Human PAP is a major histochemical marker for the diagnosis of osteoporosis. In patients suffering from this disorder, PAP activity contributes to increased bone resorption and, therefore, human PAP is a key target for the development of anti-osteoporotic drugs. This manuscript describes the design and synthesis of derivatives of 1-naphthylmethylphosphonic acids as inhibitors of PAP. The K i values of these compounds are as low as 4 lM, the lowest reported to date for a PAP inhibitor.

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Spectroscopic and magnetic studies of the purple acid phosphatase from bovine spleen

Cited by 170 publications

References 8 publications

Phosphotyrosyl peptides and analogues as substrates and inhibitors of purple acid phosphatases

Phosphotyrosyl peptides and analogues as substrates and inhibitors of purple acid phosphatases

Phosphate ester cleavage promoted by a tetrameric iron(III) complex

Inhibition of purple acid phosphatase with α-alkoxynaphthylmethylphosphonic acids

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