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Titolo:
The highly exposed loop region in mammalian purple acid phosphatase controls the catalytic activity
Autore:
Funhoff, EG; Klaassen, CHW; Samyn, B; Van Beeumen, J; Averill, BA;
Indirizzi:
Univ Amsterdam, Bioctr Amsterdam, EC Slater Inst Biochem Res, NL-1018 TV Amsterdam, Netherlands Univ Amsterdam Amsterdam Netherlands NL-1018 TV V Amsterdam, Netherlands Univ Nijmegen, Inst Cellular Signalling, Dept Biochem, NL-6500 HB Nijmegen, Netherlands Univ Nijmegen Nijmegen Netherlands NL-6500 HB 0 HB Nijmegen, Netherlands State Univ Ghent, Dept biochem Physiol & Microbiol, Lab Prot Biochem & Prot Engn, B-9000 Ghent, Belgium State Univ Ghent Ghent Belgium B-9000 & Prot Engn, B-9000 Ghent, Belgium
Titolo Testata:
CHEMBIOCHEM
fascicolo: 5, volume: 2, anno: 2001,
pagine: 355 - 363
SICI:
1439-4227(20010504)2:5<355:THELRI>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
ELECTRON-PARAMAGNETIC-RES; PROTEIN SECONDARY STRUCTURE; PIG ALLANTOIC FLUID; BOVINE SPLEEN; CRYSTAL-STRUCTURE; CIRCULAR-DICHROISM; 3-DIMENSIONAL STRUCTURE; MUTATIONAL ANALYSIS; SEQUENCE HOMOLOGY; HUMAN CALCINEURIN;
Keywords:
bioinorganic chemistry; hydrolases; metalloenzymes; proteolysis; purple acid phosphatase;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
62
Recensione:
Indirizzi per estratti:
Indirizzo: Averill, BA Univ Amsterdam, Bioctr Amsterdam, EC Slater Inst Biochem Res, Plantage Muidergracht 12, NL-1018 TV Amsterdam, Netherlands Univ Amsterdam Plantage Muidergracht 12 Amsterdam Netherlands NL-1018 TV
Citazione:
E.G. Funhoff et al., "The highly exposed loop region in mammalian purple acid phosphatase controls the catalytic activity", CHEMBIOCHEM, 2(5), 2001, pp. 355-363

Abstract

Recombinant human purple acid phosphatase (recHPAP) provides a convenient experimental system for assessing the relationship between molecular structure and enzymatic activity in mammalian purple acid phosphatases (PAPs). recHPAP is a monomeric protein with properties similar to those of uteroferrin (Uf) and other PAPs isolated as single polypeptide chains, but its properties differ significantly from those of bovine spleen PAP (BSPAP) and otherPAPs isolated as proteolytically "clipped" forms. Incubation of recHPAP with trypsin results in proteolytic cleavage in an exposed region near the active site. The product is a tightly associated two-subunit protein whose collective spectroscopic and kinetics properties resemble those of BSPAP. These results demonstrate that the differences in spectroscopic and kinetics properties previously reported for mammalian PAPs are the result of proteolytic cleavage. Mass spectrometry shows that a three-residue segment, D-V-K, within the loop region is excised by trypsin. This finding suggests that important interactions between residues in the excised loop and one or more of the groups that participate in catalysis are lost or altered upon proteolytic cleavage. Analysis of available structural data indicates that the most important such interaction is that between Asp 146 in the exposed loop and active site residues Asn 91 and His92. Loss of this interaction should result in both an, increase in the Lewis acidity of the Fel ion and an increase in the nucleophilicity of the Fe"'-bound hydroxide ion. Proteolytic cleavage thus constitutes a potential physiological mechanism for regulating the activity of PAP in vivo.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 20:22:08