Figure 3. Gel electrophoresis and calorimetric analysis of Expanded Prohead I.

(A) shows that the mobility of Prohead I in native agarose gels, after treatment with 5M urea (Expanded Prohead I), is markedly altered and perceptibly different from that of unassembled capsomers. (B) SDS-PAGE of Expanded Protein I shows a ladder of bands with mobilities corresponding to multiples of 42 kDa, indicative of a substantial degree of crosslinking of the uncleaved gp5. Also shown are a ladder of partially crosslinked gp5* (bands at multiples of 31 kDa), and gp5 monomers (not crosslinked). (C) Thermograms showing calorimetric scans of Expanded Prohead I (2^nd curve) with wild-type gp5 which is partially crosslinked (see Fig. 3B) and the non-crosslinking mutant, K169Y (3^rd curve). To allow direct comparison, the corresponding thermograms of Head II and native Prohead I are reproduced from ¹⁶ and Figure 2, respectively.