Wakita Satoshi, Kobayashi Shunsuke, Kimura Masahiro, Kashimura Akinori, Honda Shotaro, Sakaguchi Masayoshi, Sugahara Yasusato, Kamaya Minori, Matoska Vaclav, Bauer Peter O, Oyama Fumitaka
Department of Chemistry and Life Science, Kogakuin University, Hachioji, Tokyo, Japan.
Department of Applied Chemistry, Kogakuin University, Hachioji, Tokyo, Japan.
FEBS Lett. 2017 Oct;591(20):3310-3318. doi: 10.1002/1873-3468.12798. Epub 2017 Aug 30.
Mouse acidic mammalian chitinase (AMCase) degrades chitin with highest efficiency at pH 2.0 and is active up to pH 8.0. Here, we report that mouse AMCase also exhibits transglycosylation activity under neutral conditions. We incubated natural and artificial chitin substrates with mouse AMCase at pH 2.0 or 7.0 and analyzed the resulting oligomers using an improved method of fluorescence-assisted carbohydrate electrophoresis. Mouse AMCase produces primarily dimers of N-acetyl-d-glucosamine [(GlcNAc) ] under both pH conditions while generating transglycosylated (GlcNAc) primarily at pH 7.0 and at lower levels at pH 2.0. These results indicate that mouse AMCase catalyzes hydrolysis as well as transglycosylation and suggest that this enzyme can play a novel role under physiological conditions in peripheral tissues, such as the lungs.
小鼠酸性哺乳动物几丁质酶（AMCase）在pH 2.0时降解几丁质的效率最高，在pH 8.0时仍具有活性。在此，我们报告小鼠AMCase在中性条件下也表现出转糖基化活性。我们在pH 2.0或7.0条件下，将天然和人工几丁质底物与小鼠AMCase一起孵育，并使用改进的荧光辅助碳水化合物电泳方法分析产生的寡聚物。在两种pH条件下，小鼠AMCase主要产生N-乙酰-D-葡萄糖胺[（GlcNAc）]二聚体，而主要在pH 7.0时产生转糖基化的（GlcNAc），在pH 2.0时产生的水平较低。这些结果表明，小鼠AMCase催化水解以及转糖基化反应，并表明该酶在诸如肺等外周组织的生理条件下可以发挥新的作用。
