Towards control of aggregational behaviour of a-Lactalbumin at acidic pH
Towards control of aggregational behaviour of a-Lactalbumin at acidic pH
Engineering Village 2
? 2006 Elsevier Inc
Accession number: 062910012013
Title: Towards control of aggregational behaviour of a-Lactalbumin at acidic pH
Authors: Pedersen, Jane B.; Fojan, Peter; Sorensen, John; Petersen, Steffen B.
Serial title: Journal of Fluorescence
Abbreviated serial title: J Fluoresc
Volume: v 16
Issue: n 4
Issue date: July 2006
Publication year: 2006
Pages: p 611-621
Language: English
ISSN: 1053-0509
CODEN: JOFLEN
Document type: Journal article (JA)
Publisher: Springer Science and Business Media Deutschland GmbH, Berlin, 14197, Germany
Abstract: a-Lactalbumin (a-La) undergoes considerable structural changes upon loss of bound Ca2+ at acidic pH, leaving a-La in a molten globule structure. Using fluorescence the present work provides more insight into the structural transition of a-La at acidic pH leading to protein aggregation, most likely caused by a combination of hydrophobic and electrostatic interactions. The rate of aggregation is determined by the protein concentration and temperature applied. Availability of Ca2+ stabilises the protein, and thus prevent aggregation at pH values as low as pH 2.9. In contrast, presence of Cu2+ induces a destabilisation of the protein, which can be explained by a binding to the Zn2+ binding site in a-La, possibly resulting in structural alterations of the protein. In general, presence of anions destabilise a-La at pH values below pI, with SO4 2- exhibiting the strongest effect on the protein stability, thus correlating well with the Hofmeister series. At more acidic pH values far from pI, a-La becomes more stable towards ion induced aggregation, since higher ion activity is required to efficiently screen the charges on the protein surface. The results presented in this paper provide detailed knowledge on the external parameters leading to aggregation of a-La at acidic pH, thus permitting rational design of the aggregation process.
Number of references: 27
Ei main heading: Proteins
Ei controlled terms: Agglomeration - pH effects - Acidity - Fluorescence - Hydrophobicity - Electrostatics
Uncontrolled terms: a-Lactalbumin - Protein aggregation - Acrylamide quenching - Fluorescence spectroscopy - Confocal microscopy
Ei classification codes: 804.1 Organic Compounds - 802.3 Chemical Operations - 801.1 Chemistry, General - 741.1 Light/Optics - 701.1 Electricity: Basic Concepts & Phenomena
Treatment: Experimental (EXP)
DOI: 10.1007/s10895-006-0088-6
Database: Compendex
Compilation and indexing terms, ? 2006 Elsevier Inc. All rights reserved
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