Periplaneta americana Arginine Kinase as a Major Cockroach Allergen among Thai Patients with Major Cockroach Allergies

摘要

Periplaneta americana is the predominant cockroach (CR) species and a major source of indoor allergens in Thailand.Nevertheless,data on the nature and molecular characteristics of its aller-genic components are rare.We conducted this study to identify and characterize the P.americana allergenic protein.A random heptapeptide phage display library and monoclonal antibody (MAb) specific to a the P.americana component previously shown to be an allergenic molecule were used to identify the MAb-bound mimotope and its phylogenic distribution.Two-dimensional gel elec-trophoresis,liquid chromatography,mass spectrometry,peptide mass fingerprinting,and BLAST search were used to identify the P.americana protein containing the MAb-specific epitope.We studied the allergenicity of the native protein using sera of CR-allergic Thai patients in immunoassays.The mimotope peptide that bound to the MAb specific to P.americana was LTPCRNK.The peptide has an 83-100% identity with proteins of Anopheles gambiae,notch homolog scalloped wings of Lucilia cuprina,delta protein of Apis mellifera;neu5Ac synthase and tyrosine phosphatase of Drosophila melanogaster,and a putative protein of Drosophila pseudoob-scura.This finding implies that the mimotope-containing molecule of P.americana is a pan-insect protein.The MAb-bound protein of P.americana was shown to be arginine kinase that reacted to IgE in the sera of all of the CR-allergic Thai patients by immunoblotting,implying its high allergenicity.In conclusion,our results revealed that P.americana arginine kinase is a pan-insect protein and a major CR allergen for CR-allergic Thai patients.