Influence of extraction method on protein profile of soybeans

Abstract

Comparison between protein profiles of soybean obtained by commonly used methods of extraction (Tris buffer and Tris-urea buffer) with methods used for extraction of plant proteins for 2D PAGE analysis (direct solubilization in IEF buffer, acetone extraction, phenol extraction, extraction with urea solubilization buffer and thiourea-urea extraction) was investigated. 2D profiles of samples extracted directly in IEF buffer, in urea solubilization buffer and in acetone were characterized with low number of spots. Analysis of 2D PAGE profiles of Tris buffer and Tris-urea buffer extracts showed high degree of horizontal and vertical streaking. Thiourea-urea extraction gave the highest number of less intense protein spots than phenol extraction. Method of choice, due to a large number of intense spots, would be phenol extraction. [Projekat Ministarstva nauke Republike Srbije, br. TR 31022]

Keywords

• soybean proteins
• 2D PAGE analysis
• extraction
• densitometry
• isoelectric focusing