The phosphorylation and characterisation of soybean isolate and its ?-conglycinin component by casein kinase II

✍ Scribed by Burghoffer, Chantal; Chardot, Thierry; Meunier, Jean-Claude

• Book ID: 101225509
• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 97 KB
• Volume: 79
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(19990701)79:9<1179::aid-jsfa345>3.0.co;2-q

✦ Synopsis

A commercial soybean isolate was phosphorylated using casein kinase II puri®ed from the yeast Yarrowia lipolytica. Both major reserve proteins, b-conglycinin and glycinin, were phosphorylated in a sequential way. The soybean isolate incorporated up to 0.7 mol phosphate per mole in 2 h. It was found that the phosphoester bonds were stable over time. The solubility of the phosphorylated isolate with respect to pH was not dramatically increased in comparison with the native one. However, counting the radioactivity of 32 P incorporated into the proteins (only the solubility of the phosphorylated proteins was measured in this case) showed that the solubility of the proteins was dramatically improved (up to 90% solubility for phosphorylated b-conglycinin at pH 4). b-Conglycinin became more soluble in the presence of CaCl 2 upon phosphorylation; this was not the case for the isolate. The iron-binding capacity of the soy isolate and b-conglycinin was signi®cantly improved after phosphorylation (two and six times respectively).