Linked Life Data

21398173

Source:http://linkedlifedata.com/resource/pubmed/id/21398173

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2011-4-18
pubmed:abstractText
Fourier transform infrared (FT-IR)- and UV-circular dichroism (UV-CD) spectroscopy have been used to study real-time proteolytic digestion of ?-lactoglobulin (?-LG) and ?-casein (?-CN) by trypsin at various substrate/enzyme ratios in D(2)O-buffer at 37°C. Both techniques confirm that protein substrate looses its secondary structure upon conversion to the peptide fragments. This perturbation alters the backbone of the protein chain resulting in conformational changes and degrading of the intact protein. Precisely, the most significant spectral changes which arise from digestion take place in the amide I and amide II regions. The FT-IR spectra for the degraded ?-LG show a decrease around 1634 cm(-1), suggesting a decrease of ?-sheet structure in the course of hydrolysis. Similarly, the intensity around the 1654 cm(-1) band decreases for ?-CN digested by trypsin, indicating a reduction in the ?-helical part. On the other hand, the intensity around ?1594 cm(-1) and ?1406 cm(-1) increases upon enzymatic breakdown of both substrates, suggesting an increase in the antisymmetric and symmetric stretching modes of free carboxylates, respectively, as released digestion products. Observation of further H/D exchange in the course of digestion manifests the structural opening of the buried groups and accessibility to the core of the substrate. On the basis of the UV-CD spectra recorded for ?-LG and ?-CN digested by trypsin, the unordered structure increases concomitant with a decrease in the remaining structure, thus, revealing breakdown of the intact protein into smaller fragments. This model study in a closed reaction system may serve as a basis for the much more complex digestion processes in an open reaction system such as the stomach.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1873-3557
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier B.V. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
104-11
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Real time observation of proteolysis with Fourier transform infrared (FT-IR) and UV-circular dichroism spectroscopy: watching a protease eat a protein.
pubmed:affiliation
Institute of Biophysics, Johann Wolfgang Goethe Universität, Frankfurt am Main, Germany. gunnur.guler@biophysik.uni-frankfurt.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't