Un Sunjin, Jeong Kyoung Yong, Yi Myung-hee, Kim Chung-ryul, Yong Tai-Soon
Department of Environmental Medical Biology and Institute of Tropical Medicine, Korea National Arthropods of Medical Importance Resource Bank, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea.
Protein Pept Lett. 2010 Sep;17(9):1170-6. doi: 10.2174/092986610791760432.
Bla g 6, a German cockroach allergen, shows homology to muscle protein troponin C. It contains four calcium-binding domains at amino acid (aa) residues 20-30, 56-67, 96-107, and 132-143, and its immunoglobulin E (IgE) reactivity is dependent upon calcium ion level. However, the IgE binding epitopes of Bla g 6 have not been investigated. This study aimed to analyze the IgE binding epitopes from the five peptide fragments of Bla g 6. The full-length of three Bla g 6 isoallergens (Bla g 6.0101, Bla g 6.0201, and Bla g 6.0301) and five peptide fragments (P1: aa 1-111, P2: aa 1-95, P3: aa 33-111, P4: aa 80-151, and P5: aa 33-151) of Bla g 6.0101 were generated by polymerase chain reaction (PCR) and expressed in Escherichia coli. Enzyme-linked immunosorbent assay (ELISA) was performed on 24 patients' sera that adjusted the final concentration 10 mM of CaCl(2) to determine the IgE activities of Bla g 6. Eight sera (33.3%), 9 sera (37.5%), and 11 sera (45.8%) showed IgE reactivity to Bla g 6.0101, Bla g 6.0201, and Bla g 6.0301, respectively. Among the sera from the positive IgE reactivity, three patients' sera were selected and the IgE reactivity was measured by ELISA with the five peptide fragments of Bla g 6. Based on IgE responses, one patient's serum exhibited the strongest IgE reactivity. We assumed that the aa between 96-151 residues, including the calcium binding domains III and IV, would be important for IgE binding. These results may provide information that will yield safe diagnostic methods and immunotherapeutics.
德国小蠊过敏原Bla g 6与肌肉蛋白肌钙蛋白C具有同源性。它在氨基酸（aa）残基20 - 30、56 - 67、96 - 107和132 - 143处含有四个钙结合结构域，其免疫球蛋白E（IgE）反应性取决于钙离子水平。然而，尚未对Bla g 6的IgE结合表位进行研究。本研究旨在分析Bla g 6五个肽片段的IgE结合表位。通过聚合酶链反应（PCR）生成了三种Bla g 6同种变应原（Bla g 6.0101、Bla g 6.0201和Bla g 6.0301）的全长以及Bla g 6.0101的五个肽片段（P1：aa 1 - 111、P2：aa 1 - 95、P3：aa 33 - 111、P4：aa 80 - 151和P5：aa 33 - 151），并在大肠杆菌中表达。对24例患者血清进行酶联免疫吸附测定（ELISA），将氯化钙最终浓度调整为10 mM，以确定Bla g 6的IgE活性。分别有8份血清（33.3%）、9份血清（37.5%）和11份血清（45.8%）对Bla g 6.0101、Bla g 6.0201和Bla g 6.0301显示出IgE反应性。在IgE反应阳性的血清中，选择了3例患者的血清，并用Bla g 6的五个肽片段通过ELISA测量其IgE反应性。基于IgE反应，1例患者的血清表现出最强的IgE反应性。我们推测包括钙结合结构域III和IV在内的96 - 151残基之间的氨基酸对于IgE结合很重要。这些结果可能为产生安全的诊断方法和免疫疗法提供信息。
