Table 2. Infectivity of MVM mutated at interfacial residues.

Virus	Heat-induced rearrangement*	Capsid protein expression†	Capsid assembly in infected cells‡	Normalized virus titer**
Wild-type	Yes	++	++	1
F55A	Yes	++	–	<8 × 10–6
H72A	Yes	++	–	<8 × 10–7
R83A	Yes	++	+/–	<5 × 10–6
N74A	Yes	++	++	0.93
I84A	Yes	++	++	0.08
I167A	Yes	++	++	0.07
K204A	Yes	++	++	1.05
I207A	Yes	++	++	0.11
K241A	Yes	++	++	0.93
V40A	No	++	++	1.2 × 10–4
S43A	No	++	++	<4 × 10–5
N149A	No	++	++	<8 × 10–7
N170A	No	++	++	<5 × 10–6
D263A	No	++	++	<8 × 10–6

++, signal comparable with wild type; +/–, positive but very weak signal; –, signal indistinguishable from the background.

^*Determined by intrinsic tryptophan fluorescence of the capsid

^†Determined by intracellular immunofluorescence assays with an anti-VP2 Ab

^‡Determined by intracellular immunofluorescence assays with an anticapsid Ab

^**Determined in plaque-formation assays. For normalization, the average absolute titer was divided by the average titer obtained for the wild-type virus in the same experiment. For any given mutant, except K241A and V40A, the weighted average of two experiments is indicated. SD within an experiment were ≈10% of the average titer. Titers obtained in different experiments generally differed by 5–10%