A protein gives a single band on SDS gel electrophoresis, as shown in lanes 1 and 2 below There is little if any effect from adding Icirc sup2 mercaptoethanol (BME) to the sample if anything, the protein runs a little bit slower When treated with the proteolytic enzyme thrombin and electrophoresis ...

The fact that disulfide reduction has little effect means that the ...

A protein gives a single band on SDS gel electrophoresis, as shown in lanes 1 and 2

Question:

A protein gives a single band on SDS gel electrophoresis, as shown in lanes 1 and 2 below. There is little if any effect from adding Î² -mercaptoethanol (BME) to the sample; if anything, the protein runs a little bit slower. When treated with the proteolytic enzyme thrombin and electrophoresis in the absence of BME, the protein migrates a bit more rapidly (lane 3). But if BME is present, two much more rapidly migrating bands are found (lane 4). Explain these results in terms of a model for the protein.