Glutamate dehydrogenase, molecular weight

Figure 2. SDS gel electrophoresis of the products of partial cystine cleavage for several test proteins. A. molecular weight standards, B. yeast alcohol dehydrogenase. C. P-lactoglobulin, D. hen egg lysozyme, E. ovalbumin, F. calf fetal serum fetuin. Molecular weight standards are indicated by arrows on the left side of the gel and are bovine serum albumin (66,300), bovine liver glutamate dehydrogenase (55,400), porcine muscle lactate ddiydiogenase (36,500), bovine erythrocyte carbonic anhydrase (31,000), soybean trypsin inhibitor (21,500), hen egg lysozyme (14,400), bovine lung aprotinin (6,000), unresolved bovine pancreatic insulin A and B chains.

A. Lane 1, Molecular weight markers lane 2, Purified final product. Molecular mass markers are Novex SeeBlue Pre-Stained Standards and range as follows (from top to bottom) Myosin, 250-kDa BSA, 98-kDa Glutamic dehydrogenase, 64-kDa Alcohol dehydrogenase, 50-kDa Carbonic anhydrase, 36-kDa Myoglobin, 30-kDa Lysozyme, 16-kDa Aprotinin, 6-kDa Insulin B chain, 4 kDa. 

Enzyme Concentration and Purification. The number of existing enzymes is estimated to be more than 10,000 of which more than 100 have been purified in crystalline form and over 600 in fairly purified form. The molecular weight of enzymes varies from 12,700 (ribonuclease) to over 1,000,000 (L-glutamate dehydrogenase, d-carboxylase). All enzymes are proteins, conjugated proteins or metalloproteins containing one or more active sites per molecule. 

Appropriate markers for Vq of SEC columns are apoferritin (467 kDa), thyro-globuhn (670 kDa), and glutamic dehydrogenase (998 kDa). As markers, sodium azide and DNP-alanine are usually preferred [14, 15). The selection of the low molecular weight probe is a problem, because is unlikely to be truly independent... 

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