System allows purification of His-tagged proteins from rabbit reticulocyte lysate without co-purification of haemoglobin
One of the limitations of using rabbit reticulocyte lysate for expression of histidine-tagged (His-tagged) proteins has been overcome following the introduction of the MagZ protein purification system from Promega.
Through the use of non nickel-based MagZ binding particles, haemoglobin contamination is reduced by over 99%.
The ability to isolate His-tagged particles from rabbit reticulocyte lysate without haemoglobin consequently allows downstream applications such as fluorescence-based functional assays and protein:protein interaction studies: applications which would normally require purification from E coli-based systems.
The MagZ system can be used directly with TNT coupled transcription/translation systems, but is also suitable for use with any rabbit reticulocyte lysate-based methodology. This approach does not increase experiment times; His-tagged proteins bind to the MagZ particles in a matter of minutes. Non-bound proteins are washed away and target protein is then recovered by elution with imidazole.
The system has further flexibility by permitting optimisation of binding/wash and elution conditions to suit individual His-tagged proteins. However the paramagnetic binding particle approach enables the assay to be readily adapted for HTS.
The MagZ protein purification system complements Promega's existing His-tagged protein purification system, MagneHis which is said to be ideal for crude E coli cell lysates.
