Sukhumsiirchart Wasana, Kawanishi Sakiko, Deesukon Warin, Chansiri Kosum, Kawasaki Haruhiko, Sakamoto Tatsuji
Department of Biochemistry, Faculty of Medicine, Srinakharinwirot University, Bangkok, Thailand.
Biosci Biotechnol Biochem. 2009 Feb;73(2):268-73. doi: 10.1271/bbb.80287. Epub 2009 Feb 7.
A thermophilic pectate lyase, Pel SWU, was isolated from a culture filtrate of Bacillus sp. RN1 isolated from a hot spring in Ranong Province, Thailand. The enzyme was purified to homogeneity using cation-exchange and hydrophobic column chromatographies. The molecular mass of Pel SWU was estimated to be 33 kDa. The specific substrate was demethylated galacturonic acid. The enzyme was stable at pH 4.0-10.0 and at temperatures up to 70 degrees C in the presence of calcium and polygalacturonic acid (PGA). The optimum pH and temperature were 10.0 and 90 degrees C. The pel gene encoding Pel SWU was 1,023 bp, which corresponds to 341 amino acids. The properties of the recombinant enzyme was similar to those of Bacillus Pel SWU. Unsaturated di- and trigalacturonic acids were formed mainly as the final products of degradation by Pel SWU, as revealed by high-performance anion-exchange chromatography (HPAEC) and electrospray ionization mass spectrometry (ESI-MS) analyses. This thermophilic pectate lyase should be useful in the degradation of pectin networks at high temperature.
从泰国拉廊府温泉中分离得到的芽孢杆菌属RN1菌株的培养滤液中，分离出一种嗜热果胶酸裂解酶Pel SWU。该酶通过阳离子交换和疏水柱色谱法纯化至同质。Pel SWU的分子量估计为33 kDa。其特异性底物为脱甲基半乳糖醛酸。在存在钙和聚半乳糖醛酸（PGA）的情况下，该酶在pH 4.0 - 10.0以及高达70℃的温度下稳定。最适pH和温度分别为10.0和90℃。编码Pel SWU的pel基因长度为1023 bp，对应341个氨基酸。重组酶的性质与芽孢杆菌Pel SWU的性质相似。通过高效阴离子交换色谱（HPAEC）和电喷雾电离质谱（ESI-MS）分析表明，不饱和二半乳糖醛酸和三半乳糖醛酸主要作为Pel SWU降解的最终产物形成。这种嗜热果胶酸裂解酶在高温下对果胶网络的降解应该是有用的。
