Isolation and identification of hevein as a major IgE-binding polypeptide in Hevea latex.
BACKGROUND
Polypeptides in Hevea latex are known as the major cause of latex type I sensitivities. So far, only a few of them have been characterized.


METHODS
Proteins with a molecular weight lower than 10 kd in fresh Hevea latex were separated by ultrafiltration and further characterized by liquid chromatography on-line-coupled electrospray mass spectrometry. Hevein in this fraction was then purified by preparative reverse-phase high-performance liquid chromatography and characterized by matrix-assisted laser desorption ionization mass spectrometry and protein sequencing. Skin prick tests, enzyme-linked allergosorbent tests, and inhibition immunoblotting were performed to show the allergenicity of the purified hevein.


RESULTS
Hevein, a 4.7 kd polypeptide, is the predominant component in the fraction with latex proteins of smaller than 10 kd. Specific IgE antibodies to hevein were detected by enzyme-linked allergosorbent test in 48 of 64 (75%) sera from health care workers allergic to latex and in three of 11 (27%) sera from patients with spina bifida and hypersensitivity reactions to latex. Inhibition immunoblotting demonstrated that the preincubation of 14 sera and a serum pool from patients allergic to latex with purified hevein completely inhibited IgE binding to the 20 kd protein, which has been recently reported to be a major allergen in latex (prohevein). Skin prick testing showed a positive reaction to hevein in 17 of 21 (81%) patients with latex allergy.


CONCLUSIONS
The results clearly demonstrate that hevein is an important latex allergen, and the IgE-binding capacity of prohevein in latex is mostly attributed to hevein, the N-terminal domain of prohevein.
Chen
Z
Z
Research Institute for Occupational Medicine (BGFA), Ruhr-University of Bochum, Germany.
Posch
A
A
Lohaus
C
C
Raulf-Heimsoth
M
M
Meyer
H E
HE
Baur
X
X
D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D019138:Antibodies, Blocking / Q000276:immunology; D023181:Antimicrobial Cationic Peptides; D002648:Child; D002675:Child, Preschool; D002853:Chromatography, Liquid; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology; D007840:Latex / Q000737:chemistry* / Q000276:immunology*; D037102:Lectins / Q000276:immunology* / Q000302:isolation & purification*; D008297:Male; D013058:Mass Spectrometry; D008503:Medical Staff; D009784:Occupational Diseases / Q000276:immunology*; D037121:Plant Lectins; D010940:Plant Proteins / Q000276:immunology* / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D012882:Skin Tests; D016135:Spinal Dysraphism / Q000097:blood / Q000150:complications / Q000276:immunology; D014462:Ultrafiltration
D019138:Antibodies, Blocking; D023181:Antimicrobial Cationic Peptides; D007840:Latex; D037102:Lectins; D037121:Plant Lectins; D010940:Plant Proteins; C045875:hevein; D007073:Immunoglobulin E