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PURIFICATION AND PROPERTIES OF MALT CARBOXYPEPTIDASES ATTACKING HORDEIN
Author(s) -
Baxter E. D.
Publication year - 1978
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/j.2050-0416.1978.tb03886.x
Subject(s) - carboxypeptidase , hordein , endosperm , mashing , chemistry , biochemistry , hydrolysis , prolamin , amino acid , chromatography , enzyme , storage protein , gene
Carboxypeptidases capable of releasing amino acids from barley hordein have been extracted and purified from malted barley. Three enzymes can be distinguished, with similar molecular weights but slightly different ionic characteristics and specificities. The malt carboxypeptidases preferentially attack peptides containing an aromatic amino acid, although other peptides, including those containing proline, are also attacked. The purified carboxypeptidase fractions reduce the viscosity of β‐glucan extracted from endosperm cell walls. It is suggested that these enzymes may be instrumental in the initial solubilization of endosperm cell walls, possibly by the hydrolysis of the peptide component of these walls. The pH optima and heat stability data indicate that carboxypeptidases are crucial for the release of amino acids both from hordein, and from peptides derived from hordein during both malting and mashing.