Solubilization and electrophoretic characterization of select edible nut seed proteins.
The solubility of almond, Brazil nut, cashew nut, hazelnut, macadamia, pecan, pine nut, pistachio, walnut, and peanut proteins in several aqueous solvents was qualitatively and quantitatively assessed. In addition, the effects of extraction time and ionic strength on protein solubility were also investigated. Electrophoresis and protein determination (Lowry, Bradford, and micro-Kjeldahl) methods were used for qualitative and quantitative assessment of proteins, respectively. Depending on the seed, buffer type and ionic strength significantly affected protein solubility. The results suggest that buffered sodium borate (BSB; 0.1 M H(3)BO(3), 0.025 M Na(2)B(4)O(7), 0.075 M NaCl, pH 8.45) optimally solubilizes nut seed proteins. Qualitative differences in seed protein electrophoretic profiles were revealed. For a specific seed type, these differences were dependent on the solvent(s) used to solubilize the seed proteins. SDS-PAGE results suggest the polypeptide molecular mass range for the tree nut seed proteins to be 3-100 kDa. The results of native IEF suggested that the proteins were mainly acidic, with a pI range from >4.5 to <7.0. Western immunoblotting experiments indicated that rabbit polyclonal antibodies recognized substantially the same polypeptides as those recognized by the corresponding pooled patient sera IgE.
Sathe
Shridhar K
SK
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida 32306-1493, USA. ssathe@fsu.edu
Venkatachalam
Mahesh
M
Sharma
Girdhari M
GM
Kshirsagar
Harshal H
HH
Teuber
Suzanne S
SS
Roux
Kenneth H
KH
D000818:Animals; D000906:Antibodies / Q000276:immunology; D001881:Borates; D004586:Electrophoresis; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007525:Isoelectric Focusing; D021184:Nut Hypersensitivity / Q000276:immunology; D009754:Nuts / Q000737:chemistry*; D009994:Osmolar Concentration; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology; D011817:Rabbits; D012639:Seeds / Q000737:chemistry*; D012995:Solubility
D000906:Antibodies; D001881:Borates; D010940:Plant Proteins; D007073:Immunoglobulin E; C010634:sodium borate