Source:http://linkedlifedata.com/resource/pubmed/id/16768388
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
6
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pubmed:dateCreated |
2006-6-13
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pubmed:abstractText |
In this study, we use FTIR spectroscopy to probe the conformational changes of beta-lactoglobulin (beta-LG)-the main constituent of whey proteins-as subjected to enzymatic cross-linking by transglutaminase. We investigate both the amide I region (1600-1700 cm(-1)) and the C-H stretching region (2800-3100 cm(-1)). In the amide I region, spectra of denatured conformations of beta-LG, known to be necessary for cross-linking, differ according to the denaturation procedure, i.e., chemical or thermal treatment. Denaturation by chemical denaturants, dithiothreitol (DTT) or beta-mercaptoethanol, show no effect on the alpha-helix, while shifting the monomer dimer equilibrium toward higher monomer concentration. On the other hand, denaturing by thermal treatment dissociates the beta-sheets in the native structure, leading to new intermolecular beta-sheets being formed. Preheated then enzyme cross-linked beta-LG molecules show very similar spectra in the amide I region to the molecules with no cross-linking, indicating minimal effects of the cross-links on the carbonyl stretching mode. However, chemically denatured (using beta-mercaptoethanol) then enzyme cross-linked beta-LG molecules show noticeable diminution in the alpha-helix band and formation of strong hydrogen-bonded intermolecular beta-sheets. In the C-H stretching region, preheated then enzyme cross-linked beta-LG molecules exhibit a different degree of exposure of aliphatic amino acids due to the enzyme action. The same behavior is observed for DTT-treated then enzyme cross-linked beta-LG molecules. Generally, the changes in the C-H stretching region clearly indicate that hydrophobic interactions are altered upon enzymatic cross-linking.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jun
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pubmed:issn |
1525-7797
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
7
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1707-13
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:16768388-Amides,
pubmed-meshheading:16768388-Cross-Linking Reagents,
pubmed-meshheading:16768388-Lactoglobulins,
pubmed-meshheading:16768388-Models, Molecular,
pubmed-meshheading:16768388-Protein Conformation,
pubmed-meshheading:16768388-Protein Structure, Secondary,
pubmed-meshheading:16768388-Sensitivity and Specificity,
pubmed-meshheading:16768388-Spectroscopy, Fourier Transform Infrared,
pubmed-meshheading:16768388-Transglutaminases
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pubmed:year |
2006
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pubmed:articleTitle |
Enzymatic cross-linking of beta-lactoglobulin: conformational properties using FTIR spectroscopy.
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pubmed:affiliation |
Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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