Publication
Modeling the kinetics of whey protein hydrolysis brought about by enzymes from Cynara cardunculus
| dc.contributor.author | Barros, Rui M. | |
| dc.contributor.author | Malcata, F. Xavier | |
| dc.date.accessioned | 2011-10-22T15:47:28Z | |
| dc.date.available | 2011-10-22T15:47:28Z | |
| dc.date.issued | 2002 | |
| dc.description.abstract | The purpose of this research work was to study the proteolytic activity of aqueous crude extracts of flowers of the plant Cynara cardunculus on the major whey proteins, namely, â-lactoglobulin (â-Lg) and R-lactalbumin (R-La). These extracts, containing a mixture of cardosins A and B (i.e., two distinct aspartic proteases), have been employed for many years in traditional cheese-making in Portugal and Spain. Cow’s milk sweet whey was incubated for up to 24 h at various ratios of addition of crude enzyme extract, under controlled pH (5.2 and 6.0) and temperature (55 °C). The samples collected were assayed by gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A mechanistic model was proposed for the kinetics of the hydrolysis process, which is basically a double-substrate, double-enzyme Michaelis-Menten rate expression; the kinetic parameters were estimated by multiresponse, nonlinear regression analysis. The best estimates obtained for the specificity ratio (i.e., kcat/Km) of each cardosin within the mixture toward each whey protein indicated that said aspartic proteases possess a higher catalytic efficiency for R-La (0.42- 4.2 mM-1âs-1) than for â-Lg (0-0.064 mM-1âs-1), at least under the experimental conditions used. These ratios are below those previously reported for caseins and a synthetic hexapeptide. Cardosins are more active at pH 5.2 than at pH 6.0 and (as expected) at higher enzyme-to-substrate ratios. | por |
| dc.identifier.citation | BARROS, Rui M.; MALCATA, F. Xavier - Hydrolysis Brought about by Enzymes from Cynara cardunculus. Journal of Agricultural and Food Chemistry. ISSN 0021-8561. Vol. 50 (2002), p. 4347-4356 | por |
| dc.identifier.doi | 10.1021/jf0200319 | |
| dc.identifier.uri | http://hdl.handle.net/10400.14/6827 | |
| dc.language.iso | eng | por |
| dc.peerreviewed | yes | por |
| dc.publisher | American Chemical Society | por |
| dc.relation.publisherversion | http://pubs.acs.org/doi/abs/10.1021/jf0200319 | por |
| dc.subject | Enzymes | por |
| dc.subject | Dairy products | por |
| dc.subject | Kinetic Mechanism | por |
| dc.subject | Plant Proteases | por |
| dc.title | Modeling the kinetics of whey protein hydrolysis brought about by enzymes from Cynara cardunculus | por |
| dc.type | journal article | |
| dspace.entity.type | Publication | |
| person.familyName | BARROS | |
| person.familyName | Malcata | |
| person.givenName | RUI | |
| person.givenName | Francisco | |
| person.identifier.ciencia-id | 111D-8A7B-0ED1 | |
| person.identifier.ciencia-id | 1B13-38A5-35F5 | |
| person.identifier.orcid | 0000-0001-5123-2918 | |
| person.identifier.orcid | 0000-0003-3073-1659 | |
| person.identifier.rid | J-3340-2015 | |
| person.identifier.scopus-author-id | 7102542478 | |
| rcaap.rights | restrictedAccess | por |
| rcaap.type | article | por |
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