Allergy to castor bean. II. Identification of the major allergens in castor bean seeds.
Castor bean proteins were separated and identified by isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto nitrocellulose paper. The capacity of the castor bean proteins to bind human IgE was probed with sera from castor bean-sensitive patients and radiolabeled anti-IgE. It proved difficult to identify allergens with isoelectric focusing. However, three allergens were identified when proteins were first separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis: the 2S storage albumin, the 11S crystalloid proteins, and a third protein doublet with molecular weights of 47 and 51 kd. Specific IgE antibody to the 2S storage albumin, measured by RAST, was detected in most (96%) castor bean-sensitive patients, confirming it as the major allergen. We would like to suggest that the 2S albumin be named Ric c I, that the crystalloid proteins be named Ric c II, and that the 47/51 kd doublet be named allergen 3.
Thorpe
S C
SC
Department of Medicine, UMDS, Guy's Hospital, London, England.
Kemeny
D M
DM
Panzani
R C
RC
McGurl
B
B
Lord
M
M
D000485:Allergens / Q000276:immunology*; D000906:Antibodies / Q000378:metabolism; D002367:Ricinus communis / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007073:Immunoglobulin E / Q000378:metabolism; D007525:Isoelectric Focusing; D010940:Plant Proteins / Q000302:isolation & purification; D010947:Plants, Toxic; D011852:Radioallergosorbent Test; D012278:Ricinus / Q000276:immunology*
D000485:Allergens; D000906:Antibodies; D010940:Plant Proteins; D007073:Immunoglobulin E