Skip to main content

Infrared Two-Dimensional Correlation and Principal Component Analyses Applied to β-lactoglobulin Aggregation in Water-Ethanol Solution

Buy Article:

$29.00 plus tax (Refund Policy)

Abstract:

Changes of the secondary structure of β-lactoglobulin in water-ethanol solutions were studied using infrared spectroscopy. The efficiency of both principal component analysis and two-dimensional correlation spectroscopy in avoiding spectral subtraction of water was evaluated. The kinetic curves assessed from the scores of the first principal component indicated that changes were more pronounced in 50% ethanol solution than in 5% ethanol-water solution. The spectral patterns derived from the eigenvectors made it possible to characterize changes in the secondary structure of the protein. While aggregation was obtained in 50% ethanol solution, α-helices were formed at the detriment of turns in 5% ethanol solution. The two-dimensional correlation spectroscopy provided information on the sequence of events that occurred by adding ethanol to aqueous solutions of β-lactoglobulin. In 5% ethanol solution, the disappearance of turns preceded the formation of α-helices. Moreover, a small amount of aggregates were depicted at the end of the process. Aggregation of the protein was the main event observed in 50% ethanol-water solution. This event was preceded by the disappearance of α-helices. Application of both principal component analysis and two-dimensional correlation spectroscopy to spectra recorded in H2O made it possible to detect small changes not observed on second derivative spectra collected in D2O.

Keywords: AGGREGATION; BETA-LACTOGLOBULIN; INFRARED SPECTROSCOPY; PRINCIPAL COMPONENT ANALYSIS; TWO-DIMENSIONAL CORRELATION SPECTROSCOPY

Document Type: Research Article

DOI: http://dx.doi.org/10.1366/000370202760295430

Publication date: September 1, 2002

More about this publication?
sas/sas/2002/00000056/00000009/art00012
dcterms_title,dcterms_description,pub_keyword
6
5
20
40
5

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more