Inhibition or improvement for acidic subunits fibril aggregation formation from β-conglycinin, glycinin and basic subunits

• A method of improving glycinin fibril formation ability.
• Acidic subunits fibril formation was inhibited by glycinin or basic subunits.
• β-conglycinin improved the ability of acidic subunits fibril formation.
• Basic subunits inhibited α-helix transitioning to the β-strands of acidic subunits.

It was difficult to form nice nano-fibril structure from glycinin, but in this study, we found a new method to solve the problem. The acidic subunits isolated from glycinin could form thinner, longer and more flexible fibril aggregation compared with glycinin or β-conglycinin fibril aggregation at pH2.0 and 95 °C after heating 20 h β-Conglycinin, glycinin and basic subunits were respectively mixed with acidic subunits heating at 95 °C and pH2.0 to gain insight into the influence on the formation of acidic subunits fibrils. The different soy proteins interaction was probably the main reasons for inhibition or improvement the acidic subunits fibrils formation. The morphology and kinetics of fibril formation and the change of secondary structure were analyzed by transmission electron microscopy (TEM), fluorescent dye Thioflavin T (Th T) and far-UV circular dichroism (CD) spectroscopy. These results showed that β-conglycinin improved but glycinin and its basic subunits inhibited or destroyed the formation of acidic subunits fibrils. Glycinin and its basic subunits with higher surface hydrophobicity produced more aggregation, and fast aggregate was disastrous for the formation of acidic subunits fibrils. Furthermore, CD results indicated that basic subunits probably inhibited the α-helix transition into β-strands of acidic subunits.