Mechanisms behind protein-protein interactions in a β-lg-legumin co-precipitate

TY - JOUR

T1 - Mechanisms behind protein-protein interactions in a β-lg-legumin co-precipitate

AU - Thorgaard Kristensen, Heidi

AU - Christensen , Mette

AU - Hansen, M. S:

AU - Hammershøj, Marianne

AU - Dalsgaard, Trine Kastrup

PY - 2022/3

Y1 - 2022/3

N2 - Interactions between pea protein and whey protein isolates in co-precipitates and blends consist of a combination of disulphide bonds, hydrophobic and electrostatic interactions. The present study aims to clarify if the two proteins with free thiols, β-lactoglobulin (β-lg) and legumin, played a significant role for these interactions. This study used different reagents to modify the conditions of interactions: N-ethylmaleimide (NEM) was used to block reactive thiols, while NaCl and SDS were used to prevent electrostatic or hydrophobic interactions, respectively. The effects of treatments were studied on protein solubility, structure and stability. SDS had no effect, while NEM and NaCl both had great effect, especially in combination. The results showed that interactions of β-lg and legumin in both co-precipitates and blends are a synergism of electrostatic interactions and disulphide bonds. Thus, β-lg and legumin are the main proteins responsible for previously observed interactions in protein isolates of whey and pea.

AB - Interactions between pea protein and whey protein isolates in co-precipitates and blends consist of a combination of disulphide bonds, hydrophobic and electrostatic interactions. The present study aims to clarify if the two proteins with free thiols, β-lactoglobulin (β-lg) and legumin, played a significant role for these interactions. This study used different reagents to modify the conditions of interactions: N-ethylmaleimide (NEM) was used to block reactive thiols, while NaCl and SDS were used to prevent electrostatic or hydrophobic interactions, respectively. The effects of treatments were studied on protein solubility, structure and stability. SDS had no effect, while NEM and NaCl both had great effect, especially in combination. The results showed that interactions of β-lg and legumin in both co-precipitates and blends are a synergism of electrostatic interactions and disulphide bonds. Thus, β-lg and legumin are the main proteins responsible for previously observed interactions in protein isolates of whey and pea.

KW - Co-precipitation

KW - Legumin

KW - NEM blocking

KW - Protein-protein interactions

KW - β-lactoglobulin

U2 - 10.1016/j.foodchem.2021.131509

DO - 10.1016/j.foodchem.2021.131509

M3 - Journal article

C2 - 34774378

SN - 0308-8146

VL - 373

JO - Food Chemistry

JF - Food Chemistry

IS - Part B

M1 - 131509

ER -