Transpeptidation in concentrated solution of peptic hydrolyzate of ovalbumin

✍ Scribed by Gololobov, M. Yu. ;Belikov, V. M. ;Vitt, S. V. ;Paskonova, E. A. ;Titova, E. F.

• Publisher: John Wiley and Sons
• Year: 1981
• Tongue: English
• Weight: 748 KB
• Volume: 25
• Category: Article
• ISSN: 0027-769X
• DOI: 10.1002/food.19810251011

✦ Synopsis

Abstract

The increase of viscosity inherent in the plastein reaction is not bound up with any noticeable increase of molecular weight of peptides. Electron microscopy of the reaction mixture demonstrates the formation of small insoluble particles and their subsequent aggregation caused the increase of viscosity or/and formation of precipitate. The precipitate is shown to enrich with hydrophobic amino acid residues compared to the supernatant. The increase of the turbidity of the reaction mixture after addition of 10% trichloroacetic acid with the plastein reaction course which in some publications was assumed to be an argument in favor of polycondensation may rather be attributed to the aggregation of particles since in the course of the reaction neither the absorbances at 280 nm nor a‐amino nitrogen content of trichloroacetic soluble fraction change. Therefore, the mechanism of studied plastein reaction consists in the transpeptidation and the formation of the same molecular weight peptides with increased content of hydrophobic amino acid residues.