Purification Of Topoisomerase Research Articles

A simplified protocol for high-yield expression and purification of bacterial topoisomerase I

Type IA topoisomerases represent promising antibacterial drug targets. Data exists suggesting that the two bacterial type IA topoisomerase enzymes—topoisomerase I and topoisomerase III—share an overlapping biological role. Furthermore, topoisomerase I has been shown to be essential for the survival of certain organisms lacking topoisomerase III. With this in mind, it is plausible that topoisomerase I may represent a potential target for selective antibacterial drug development. As many reported bacterial topoisomerase I purification protocols have either suffered from relatively low yield, numerous steps, or a simple failure to report target protein yield altogether, a high-yield and high-purity bacterial topoisomerase I expression and purification protocol is highly desirable. The goal of this study was therefore to optimize the expression and purification of topoisomerase I from Streptococcus mutans, a clinically relevant organism that plays a significant role in oral and extra-oral infection, in order to quickly and easily attain the requisite quantities of pure target enzyme suitable for use in assay development, compound library screening, and carrying out further structural and biochemical characterization analyses. Herein we report the systematic implementation and analysis of various expression and purification techniques leading to the development and optimization of a rapid and straightforward protocol for the auto-induced expression and two-step, affinity tag purification of Streptococcus mutans topoisomerase I yielding >20 mg/L of enzyme at over 95% purity.

A new polymer supported packing material as a substitute of hydroxylapatite: Purification of Topoisomerases

Hydroxylapatite (HA), a form of calcium phosphate, finds extensive usages in the fractionation and purification of proteins, enzymes and nucleic acids. However, commercial HA preparations for liquid chromatography (LC) differ from many other LC packing materials in that the former is not polymer supported. We have now developed a substitute packing material which uses Fractosil 200 as the polymer support. Other polymer supports can also be similarly used. Being Fractosil 200 supported, this Hydroxylapatite Substitute (HAS) matrix can be employed for open column LC as well as for HPLC purposes. Although the exact chemical nature of HAS is different from the conventional HA, HAS mimicks the functions of the latter support. Due to the highi?½ binding capacity of HA many DNA binding proteins have been partially purified on this support. In the present work HAS has been successfully used in the partial purification of Topoisomerase I and II from wheat germ.