In the purification of LDH using a Gelchromatography If your

In the purification of LDH using a Gel-chromatography If your LDH came out in more than one fraction, why might this be? Consider the tertiary structure in your answer, and remember that LDH is active in monomer, or dimer, or tetramer form.

Solution

Lactate dehydrogenase is composed of four subunits that means it is a Tetramer. Molecular weight of tetramer is about 140 kDa. Tetramer made of 2 subunit types: M and H. Molecular weight of each subunit is about 35 kDa.

As already mentioned in the question that the enzyme is active in  monomer, or dimer, or tetramer form. Because of that we can get three different fraction of the Enzyme one for tetramer, one for dimer and one for monomer because gel filtration chromatography separating protein on the basis of their size. Larger subunit will elute first followed by smaller subunit.