Role of Micronutrients on Enzyme Activity

All biological activities are mediated by enzyme activities. Enzymes are specific to their substrates and function at the optimum levels under different conditions of temperature, pH, and many times also in the presence of specific coenzymes, cofactors and a metal ion. The metal ion is converted to oxidized andor reduced state by the change of electron(s) during a biochemical reaction.

In the present experiment Pyruvate the end product was estimated in the presence its substrate and as effected by four different concentrations (0.2 mg cl 0.4 mg cl 0.5 mg cl and 0.8  mg cl) of magnesium chloride. The enzyme activity was assayed at 30 min intervals for 180 minutes.

It was observed that addition of up to 0.4 mg cl of magnesium chloride concentration the activity increased in a linear fashion even at the initial stage of the reaction (Fig 2). But at higher concentrations, 0.6 and 0.8 mg cl the enzyme activity steeply falls down and was seem to stabilize around that concentration.

It can also be seen in Fig 1 that at the same increasing concentrations of magnesium chloride, the enzyme activity proceed in a linear increasing manner till 180 minutes (Tubes 4 and 5 Fig 1 and to some extent in tube 2 (Fig 1). But in tubes 3 and 6 the activity increase is not that comparably steep.

Many enzymes need cofactors which are non-protein molecules which function by binding to show activity. Many metal ions such as iron in reduction - oxidation reactions, magnesium, copper and many more are involved actively in such reactions.

In addition to positive intimate involvements of metal ions in many biochemical reactions met als can also be strong inhibitors of enzymes. They also may be required for the start of the reaction as in the present experiments. But beyond certain concentrations of their ions their roles may become passivive, non-active or strongly inhibitory.

In the present concentrations the linear incremental trend of the enzyme up to 04 mg cl concentrations of magnesium ions was observed till the ned of the experiment in tubes 4 and 5. But in other tubes after 120 minutes magnesium is either inhibitory or is not required. It is less likely to be inhibitory because the activity proceeds without dropping albeit slow.

The present experiments reveal a trend of magnesium ions for enzyme activity with PNP as a substrate. More experiments need for obtaining specific information.


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