Document Detail


Reduction of immunoreactivity of bovine beta-lactoglobulin upon combined physical and proteolytic treatment.
MedLine Citation:
PMID:  12617393     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Bovine beta-lactoglobulin was hydrolyzed with trypsin or chymotrypsin before, during and after treatment at 600 MPa and pH 6.8 for 10 min at 30, 37 and 44 degrees C. The extent of beta-lactoglobulin hydrolysis under pressure was noticeably higher than at atmospheric pressure, particularly when chymotrypsin was used. Addition of proteases at ambient pressure to previously pressure-treated beta-lactoglobulin gave only a modest increase in proteolysis with respect to the untreated protein. Products of enzyme hydrolysis under pressure were separated by reverse-phase HPLC, and were found to be different from those obtained at atmospheric pressure when chymotrypsin was used. The residual immunochemical reactivity of the products of combined pressure-enzyme treatment was assessed on the unresolved hydrolysates by ELISA tests using polyclonal and monoclonal antibodies, and on individual hydrolytic fractions by Western Blotting using sera of paediatric patients allergic to whey proteins in cow milk. The immunoreactivity of the whole hydrolysates was related to their content of residual intact beta-lactoglobulin, and no immunochemical reactivity was found for all the products of chymotrypsin hydrolysis under pressure. The results indicate that chymotrypsin effectively hydrolysed hydrophobic regions of beta-lactoglobulin that were transiently exposed during the pressure treatments and that were not accessible in the native protein or in the protein that had been previously pressure treated.
Authors:
Francesco Bonomi; Alessandro Fiocchi; Hanne Frøkiaer; Antonella Gaiaschi; Stefania Iametti; Claudio Poiesi; Patrizia Rasmussen; Patrizia Restani; Pierpaolo Rovere
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of dairy research     Volume:  70     ISSN:  0022-0299     ISO Abbreviation:  J. Dairy Res.     Publication Date:  2003 Feb 
Date Detail:
Created Date:  2003-03-05     Completed Date:  2003-04-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  2985125R     Medline TA:  J Dairy Res     Country:  England    
Other Details:
Languages:  eng     Pagination:  51-9     Citation Subset:  IM    
Affiliation:
Dipartimento di Scienze Molecolari Agroalimentari, University of Milan, Italy.
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MeSH Terms
Descriptor/Qualifier:
Atmospheric Pressure
Blotting, Western
Chromatography, High Pressure Liquid
Chymotrypsin / metabolism*
Electrophoresis, Polyacrylamide Gel
Enzyme-Linked Immunosorbent Assay
Hydrogen-Ion Concentration
Hydrolysis
Lactoglobulins / analysis*,  chemistry,  metabolism*
Temperature
Trypsin / metabolism*
Chemical
Reg. No./Substance:
0/Lactoglobulins; EC 3.4.21.1/Chymotrypsin; EC 3.4.21.4/Trypsin

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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