Any enzyme will have a particular dependence on salts, buffer type, metal ions, other cofactors, overall ionic strength of the solution, and pH, to name just some. These are not necessarily independent variables and you will need to carefully optimize your assay conditions using a systematic approach to get more activity. This applies to any enzyme, at any temperature, and there is no magical way to improve the activity at a low temperature (or any other temperature for that matter).     

every enzyme has a optimum temperature as you know very well, and low temperature or cold temperature you con maintain your enzymes activity to do any further analysis.so you need to maintain its temperature and check what is its perfect activity temperature...

At very cold temperatures, molecules move more slowly and reduce the frequency of enzyme-substrate collisions and therefore decreasing enzyme activity. for each enzyme you need to find out  pH, temperature for optimum activity.

A research (More et al 1995) showed that glutamate dehydrogenase from Thermococcales strain AN1 and beta-glucosidase from Caldocellum saccharolyticum expressed in Escherichia coli worked even at -70 and -65 degree C respectively.

Naturally evolved enzymes, reached to the optimization at low temperature activity  via destabilization of the structures bearing the active site or by destabilization of the whole molecule. This reduced the number and strength of all types of weak interactions or the disappearance of stability factors, and results in improved dynamics of active site residues in the low temperatures. Considering the delicate or precise structural adjustments required for low temperature activity, directed evolution appears to be the most suitable methodology to engineer low temperature activity in biological catalysts.

Hi there,

Have you considered to study the homologous enzyme from a psychrophile organism?

The simplest approach is to use more enzyme as activity is lower at lower temperatures.

Osmolytes usually reduce enzymatic activity as they bind water needed as "grease" for conformational changes in the enzyme during turnover. This conformational stabilisation is also the reason why they protect proteins from denaturation.

The specific working conditions of many enzymes you can find on the enzyme database BRENDA (http://www.brenda-enzymes.info/)