Binding interactions between a-glucans from Lactobacillus reuteri and milk proteins characterised by surface plasmon resonance

TY - JOUR

T1 - Binding interactions between a-glucans from Lactobacillus reuteri and milk proteins characterised by surface plasmon resonance

AU - Diemer, Silja Kej

AU - Svensson, Birte

AU - Babol, Linnéa N.

AU - Cockburn, Darrell

AU - Grijpstra, Pieter

AU - Dijkhuizen, Lubbert

AU - Folkenberg, Ditte M.

AU - Garrigues, Christel

AU - Ipsen, Richard

PY - 2012/9

Y1 - 2012/9

N2 - Interactions between milk proteins and α-glucans at pH 4. 0-5. 5 were investigated by use of surface plasmon resonance. The α-glucans were synthesised with glucansucrase enzymes from Lactobacillus reuteri strains ATCC-55730, 180, ML1 and 121. Variations in the molecular characteristics of the α-glucans, such as molecular weight, linkage type and degree of branching, influenced the interactions with native and denatured β-lactoglobulin and κ-casein. The highest overall binding levels were reached with α-(1,4) compared to α-(1,3) linked glucans. Glucans with many α-(1,6) linkages demonstrated the highest binding levels to κ-casein, whereas the interaction with native β-lactoglobulin was suppressed by α-(1,6) linkages. Glucans with a higher degree of branching generally displayed lower protein binding levels whereas a higher molecular weight resulted in increased binding to κ-casein. The interactions with κ-casein were not pH dependent, whereas binding to denatured β-lactoglobulin was highest at pH 4. 0 and binding to native β-lactoglobulin was optimal at pH 4. 5-5. 0. This study shows that molecular weight, linkage type and degree of branching of α-glucans highly influence the binding interactions with milk proteins.

AB - Interactions between milk proteins and α-glucans at pH 4. 0-5. 5 were investigated by use of surface plasmon resonance. The α-glucans were synthesised with glucansucrase enzymes from Lactobacillus reuteri strains ATCC-55730, 180, ML1 and 121. Variations in the molecular characteristics of the α-glucans, such as molecular weight, linkage type and degree of branching, influenced the interactions with native and denatured β-lactoglobulin and κ-casein. The highest overall binding levels were reached with α-(1,4) compared to α-(1,3) linked glucans. Glucans with many α-(1,6) linkages demonstrated the highest binding levels to κ-casein, whereas the interaction with native β-lactoglobulin was suppressed by α-(1,6) linkages. Glucans with a higher degree of branching generally displayed lower protein binding levels whereas a higher molecular weight resulted in increased binding to κ-casein. The interactions with κ-casein were not pH dependent, whereas binding to denatured β-lactoglobulin was highest at pH 4. 0 and binding to native β-lactoglobulin was optimal at pH 4. 5-5. 0. This study shows that molecular weight, linkage type and degree of branching of α-glucans highly influence the binding interactions with milk proteins.

U2 - 10.1007/s11483-012-9260-5

DO - 10.1007/s11483-012-9260-5

M3 - Journal article

SN - 1557-1858

VL - 7

SP - 220

EP - 226

JO - Food Biophysics

JF - Food Biophysics

IS - 3

ER -