Extraction, purification by cation exchange supermacroporous cryogel and physico‐chemical characterization of γ‐conglutin from lupin seeds (Lupinus albus L.)

• Published in: Journal of separation science Vol. 45; no. 2; pp. 401 - 410
• Main Authors: Silva, Richard Marins, Guimarães, Valeria Monteze, Veríssimo, Lizzy Ayra Alcântara, Vidigal, Márcia Cristina Teixeira Ribeiro, Minim, Valéria Paula Rodrigues, Minim, Luis Antonio
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.01.2022
• Subjects: Cation exchanging; Cations - analysis; Chromatography; Cryogels; Denaturation; Electrophoresis; Ions; Liquid chromatography; Lupins; Lupinus - chemistry; Lupinus - metabolism; Mass spectrometry; Plant Proteins - analysis; Proteins; Purification; Seeds - chemistry; supermacroporous cryogel; white lupin; γ‐conglutin purification; supermacroporous cryogel; mass spectrometry; white lupin; γ-conglutin purification
• ISSN: 1615-9306; 1615-9314
• DOI: 10.1002/jssc.202100675

This study focused on the extraction, purification, and physicochemical characterization of γ‐conglutin, a protein present in lupin seeds with properties of reducing blood glucose levels. Total protein was extracted with an alkaline‐saline solvent, followed by isoelectric precipitation. Chromatographic purification of the precipitated fraction was performed using a cation exchange supermacroporous cryogel column. Electrophoresis of the eluted fraction from chromatography presented a single band of ∼48 kDa under non‐reducing conditions (two bands of ∼30 and ∼17 kDa, under reducing conditions) confirming the success of the purification protocol. Liquid chromatography‐tandem mass spectrometry analysis confirmed the identity of the protein as γ‐conglutin. The purified γ‐conglutin had an isoelectric point of 7.51, β‐sheets prevailing as a secondary structure, and denaturation temperature close to 68°C. The outcome of this work showed that γ‐conglutin was obtained with a high degree of purity. The proposed purification protocol is simple and can be easily scaled up.