Purification and characterization of barley dipeptidyl peptidase IV

Purification and characterization of barley dipeptidyl peptidase IV

Autor Davy, Anne Google Scholar
Thomsen, Karl Kristian Google Scholar
Juliano, Maria Aparecida Autor UNIFESP Google Scholar
Alves, Lira C. Google Scholar
Svendsen, Ib Google Scholar
Simpson, David J. Google Scholar
Instituição Carlsberg Lab
Universidade Federal de São Paulo (UNIFESP)
Resumo Barley (Hordeum vulgare L.) storage proteins, which have a high content of proline (Pro) and glutamine, are cleaved by cysteine endoproteases to yield peptides with a Pro next to the N-terminal and/or C-terminal amino acid residues. A peptidase cleaving after Xaa-Pro- at the N terminus of peptides was purified from green barley malt. It was identified as a serine-type dipeptidyl peptidase (DPP), based on inhibitor studies, and the nature of the cleavage product. It is a monomeric glycoprotein with an apparent molecular mass of 105 kD (85 kD after deglycosylation), with a pi of 3.55 and a pH optimum at 7.2. Substrate specificity was determined with a series of fluorogenic peptide substrates with the general formula Xaa-Pro-AMC, where Xaa is an unspecified amino acid and AMC is 7-amino-4-methylcoumarin. the best substrates were Xaa = lysine and arginine, while the poorest were Xaa = aspartic acid, phenylalanine, and glutamic acid. the K-m values ranged from 0.071 to 8.9 mu M, compared with values of 9 to 130 mu M reported for mammalian DPP IVs. We discuss the possible role of DPP IV in the degradation of small Pro-containing peptides transported from the endosperm to the embryo of the germinating barley grain.
Idioma Inglês
Data 2000-02-01
Publicado em Plant Physiology. Rockville: Amer Soc Plant Physiologists, v. 122, n. 2, p. 425-431, 2000.
ISSN 0032-0889 (Sherpa/Romeo, fator de impacto)
Editor Amer Soc Plant Physiologists
Extensão 425-431
Fonte http://dx.doi.org/10.1104/pp.122.2.425
Direito de acesso Acesso aberto Open Access
Tipo Artigo
Web of Science WOS:000086903000012
URI http://repositorio.unifesp.br/handle/11600/26240

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