Takai T, Hatanaka H, Ichikawa S, Yokota T, Inagaki F, Okumura Y
Bioscience Research and Development Laboratory, Asahi Breweries, Ltd., Kitasoma-gun, Ibaraki, Japan.
Biosci Biotechnol Biochem. 2001 Jul;65(7):1601-9. doi: 10.1271/bbb.65.1601.
Recently, we reported that introduction of mutations that induced conformational changes of the major mite allergen Der f 2 was an efficient strategy to reduce the allergenicity for safer allergen-specific immunotherapy. In this study, we evaluated another strategy, disruption of two independent IgE epitopes without inducing conformational change. We analyzed allergenicities of the wild-type Der f 2, two single mutants with a mutation at either of the two IgE-binding sites (K15A and K77A), and a double mutant with mutations at both of the sites (K15/77A). Purified recombinant forms of Der f 2 expressed in Escherichia coli had correct disulfide bonds, equivalent apparent molecular masses of approximately 15 kDa, and similar secondary structures. The mutants of Der f 2 had less IgE reactivities than the wild-type Der f 2 and reduced inhibitory activities for IgE-binding to the wild-type Der f 2. However, the mutations did not significantly reduce histamine-releasing activity.
最近，我们报道说引入能诱导主要螨过敏原Der f 2构象变化的突变是一种有效的策略，可降低过敏原性，以实现更安全的过敏原特异性免疫疗法。在本研究中，我们评估了另一种策略，即破坏两个独立的IgE表位而不诱导构象变化。我们分析了野生型Der f 2、在两个IgE结合位点之一发生突变的两个单突变体（K15A和K77A）以及在两个位点都发生突变的双突变体（K15/77A）的过敏原性。在大肠杆菌中表达的纯化重组形式的Der f 2具有正确的二硫键、约15 kDa的等效表观分子量和相似的二级结构。Der f 2的突变体与野生型Der f 2相比，具有较低的IgE反应性，并且对IgE与野生型Der f 2结合的抑制活性降低。然而，这些突变并没有显著降低组胺释放活性。
