Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
Bioresour Technol. 2019 Dec;293:122013. doi: 10.1016/j.biortech.2019.122013. Epub 2019 Aug 14.
Here, we show the utility of a cyanobacterial biomass for overproduction and easy downstream processing of the thermostable protein KatB (a Mn-catalase). The nitrogen-fixing blue-green alga, Anabaena, was bioengineered to overexpress the KatB protein (An-KatB). Interestingly, pure An-KatB could be isolated from Anabaena by a simple physical process, obviating the need of expensive resins or chromatographic steps. An-KatB was an efficient HO-detoxifying protein that retained all the properties of Mn-catalases. Surprisingly, the purified An-KatB showed improved characteristics than the corresponding KatB (Ec-KatB) protein purified after over-expression in E. coli. An-KatB was unaffected by exposure to high temperature (85 °C), whereas a commercially procured heme-catalase showed an appreciable drop in activity beyond 50 °C. These data convincingly demonstrate the utility of Anabaena as a competent microbial bioresource for overproduction of proteins and further highlight the advantage of An-KatB over heme-catalases in bioprocesses where HO is to be decomposed at elevated temperatures.
在这里，我们展示了一种蓝藻生物质在过表达和易于下游处理热稳定蛋白 KatB（一种 Mn-过氧化氢酶）方面的应用。固氮蓝藻鱼腥藻被生物工程改造以过表达 KatB 蛋白（An-KatB）。有趣的是，纯 An-KatB 可以通过简单的物理过程从鱼腥藻中分离出来，无需使用昂贵的树脂或色谱步骤。An-KatB 是一种高效的 HO 解毒蛋白，保留了 Mn-过氧化氢酶的所有特性。令人惊讶的是，与在大肠杆菌中过表达后纯化的相应 KatB（Ec-KatB）蛋白相比，纯化的 An-KatB 显示出更好的特性。An-KatB 不受高温（85°C）的影响，而商业采购的血红素过氧化氢酶在超过 50°C 时活性明显下降。这些数据令人信服地证明了鱼腥藻作为一种有能力的微生物生物资源，可用于过表达蛋白质，并且进一步强调了在需要在高温下分解 HO 的生物工艺中，An-KatB 相对于血红素过氧化氢酶的优势。
