title: Extraction, purification and identification of antifreeze proteins from cold acclimated malting barley (Hordeum vulgare L.).
abstract: Antifreeze proteins from cold-acclimated malting barley were extracted by infiltration-centrifugation. The infiltration time was optimised, and its extraction effect was evaluated. The effect of cold acclimation on the accumulation of barley antifreeze proteins (BaAFPs) was assessed by comparing the thermal hysteresis activities (THA) of proteins extracted from both cold acclimated and non-cold acclimated barley grain. Ultra-filtration, ammonium precipitation and column chromatography were used successively to purify the BaAFPs, and MALDI-TOF-MS/MS was used for protein identification. The results showed that infiltration-centrifugation was more targeted than the traditional method, and 10h was the optimal infiltration time. THA was observed only after cold acclimation implied that AFPs only began to accumulate after cold acclimation. After purification, BaAFP-I was obtained at an electrophoresis level and its THA was 1.04°C (18.0 mg ml(-1)). The mass fingerprinting and sequencing results indicated the homology of the BaAFP-I to alpha-amylase inhibitor BDAI-1 (Hordeum vulgare).
authors.affiliation: State Key Laboratory of Food Science and Technology & School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, PR China.
authors.forename: Xiangli
authors.initials: X
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Food Science and Technology & School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, PR China. Electronic address: zhanghui@jiangnan.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment & Technology & School of Mechanical Engineering, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, PR China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Food Science and Technology & School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Food Science and Technology & School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, PR China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Food Science and Technology & School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, PR China.
authors.forename: Xiguang
authors.initials: X
authors.lastname: Qi
mesh_terms: D021301:Antifreeze Proteins / Q000737:chemistry* / Q000302:isolation & purification; D003080:Cold Temperature; D001467:Hordeum / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D021301:Antifreeze Proteins
keywords: 2-Mercaptoethanol (PubChem CID: 1567); Ammonium sulphate (PubChem CID: 6097028); Antifreeze proteins; Barley (Hordeum vulgare L.); Bromophenol blue (PubChem CID: 8272); Cold acclimate; Disodium phosphate dodecahydrate (PubChem CID: 61456); Glycerol (PubChem CID: 753); Hydrochloric acid (PubChem CID: 313); Identification; Infiltration–centrifugation; Purification; Sodium chloride (PubChem CID: 5234); Sodium dihydrogen phosphate (PubChem CID: 23673460); Tromethamine (PubChem CID: 6503)