Effect of soluble soybean protein hydrolysate-calcium complexes on calcium uptake by Caco-2 cells.
Soybean protein hydrolysates (SPHs) bind with calcium, forming soluble SPH-calcium complexes via the carboxyl groups of glutamic and aspartic acid residues. However, their effect on calcium uptake is still unclear. In this study, Caco-2 cells were used to estimate the effect of SPH-calcium complexes with different molecular weights on calcium uptake in vitro. The changes in intracellular calcium ion concentration were measured by Fura-2 loading and expressed in fluorescence intensity. SPH-calcium complexes could promote calcium uptake. Improved fluorescence intensity was significantly different in SPH-calcium complexes (10 to 30 kDa), SPH-calcium complexes (3 to 10 kDa), and SPH-calcium complexes (1 to 3 kDa). The maximum levels of relative fluorescence intensity (18.3) occurred with SPH-calcium complexes (10 to 30 kDa). The effect of SPH-calcium complexes (10 to 30 kDa) on Ca(2+) increase was determined to be concentration dependent in the range of 0.5 to 4 mg/mL. Our results indicate that soybean protein itself might be responsible for promoting calcium absorption.
Lv
Y
Y
College of Food Science and Nutritional Engineering, China Agricultural Univ, Haidian District, Beijing, PR China.
Bao
X-L
XL
Yang
B-C
BC
Ren
C-G
CG
Guo
S-T
ST
D000042:Absorption; D018938:Caco-2 Cells; D002118:Calcium / Q000378:metabolism*; D016257:Fura-2 / Q000378:metabolism; D006801:Humans; D008970:Molecular Weight; D011492:Protein Hydrolysates / Q000378:metabolism*; D030262:Soybean Proteins / Q000378:metabolism*
D011492:Protein Hydrolysates; D030262:Soybean Proteins; D002118:Calcium; D016257:Fura-2