Kaneko S, Kitaoka M, Kuno A, Hayashi K
NationalFood Research Institute, Ministry of Agriculture, Forestry, and Fisheries, Ibaraki, Japan.
Biosci Biotechnol Biochem. 2000 Apr;64(4):741-5. doi: 10.1271/bbb.64.741.
4-Methylumbelliferyl-beta-D-xylobioside (MU-X2) and 5-bromo-3-indolyl-beta-D-xylobioside (BI-X2) were synthesized as substrates for the detection of xylanase activity on agar plates. A family F/10 xylanase from Streptomyces olivaceoviridis E-86 (FXYN) was able to be more sensitively detected than RBB-xylan by using MU-X2 as a substrate. A mutant xylanase E128H/FXYN having only 1/1000 of the activity of FXYN was also able to be detected on the MU-X2 plate but was not detected on the RBB-xylan plate. A family G/11 xylanase from Streptomyces lividans 66 (Xyn B) was not detected on the MU-X2 plate, but it was able to be detected on the RBB-xylan plate, suggesting that the MU-X2 substrate is specific to family F/10 xylanases. However, none of the xylanases were detected effectively by using BI-X2 as a substrate.
合成了4-甲基伞形酮基-β-D-木二糖苷（MU-X2）和5-溴-3-吲哚基-β-D-木二糖苷（BI-X2）作为在琼脂平板上检测木聚糖酶活性的底物。来自橄榄绿链霉菌E-86（FXYN）的F/10家族木聚糖酶，以MU-X2为底物时比以RBB-木聚糖为底物时能更灵敏地被检测到。活性仅为FXYN千分之一的突变木聚糖酶E128H/FXYN在MU-X2平板上也能被检测到，但在RBB-木聚糖平板上未被检测到。来自变铅青链霉菌66（Xyn B）的G/11家族木聚糖酶在MU-X2平板上未被检测到，但在RBB-木聚糖平板上能被检测到，这表明MU-X2底物对F/10家族木聚糖酶具有特异性。然而，以BI-X2为底物时，没有一种木聚糖酶能被有效检测到。
