Modern Experimental Biochemistry 3rd Edition by Rodney Boyer

Exercise 5

A protein with molecular weight of 100,000 shows a single boundary when centrifuged in aqueous buffer. If the protein is centrifuged in a medium of the same buffer plus 6 M urea, two boundaries are ob­served, one corresponding to a molecular weight of 10,000, the other 30,000. The area of the slower peak is two-thirds that of the faster. De­scribe the subunit structure of the protein.