Interaction of human alpha-lactalbumin with fatty acids: determination of binding parameters.
The interaction of holo- and apo-forms of human alpha-lactalbumin with fatty acids was studied by a partition equilibrium method. Apo-alpha-lactalbumin, obtained by treatment with EDTA, displays one binding site for fatty acids, the association constants for oleic and palmitic acids being 1.9.10(6) and 4.2.10(5) M(-1), respectively. However, holo-alpha-lactalbumin was unable to bind fatty acids as measured by this technique. Likewise, no fatty acids bound to holo-alpha-lactalbumin, isolated using nondenaturing conditions, were detected by gas chromatography. These results demonstrate that the conformational change induced in alpha-lactalbumin by the removal of calcium enables the protein to interact with fatty acids.
Barbana
C
C
Tecnologia y Bioquimica de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza 50013, Spain. barbana@unizar.es
Pérez
M D
MD
Pocovi
C
C
Sánchez
L
L
Wehbi
Z
Z
D005591:Chemical Fractionation; D005227:Fatty Acids / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D007768:Lactalbumin / Q000737:chemistry* / Q000378:metabolism*; D008895:Milk, Human / Q000737:chemistry; D019301:Oleic Acid / Q000737:chemistry / Q000378:metabolism; D019308:Palmitic Acid / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding
D005227:Fatty Acids; D019301:Oleic Acid; D019308:Palmitic Acid; D007768:Lactalbumin