Structural analysis of herpes simplex virus by optical super-resolution imaging

Laine, Romain F.; Albecka, Anna; van de Linde, Sebastian; Rees, Eric J.; Crump, Colin M.; Kaminski, Clemens F.

As our analysis takes into account the linker size, different labelling strategies should lead to the same results. Any differences can then be interpreted as deviations from the model (in particular, non-spherical or non-random distribution) or direct effect of the labelling on the particles (labelling affecting the particle size, for instance). In fact, we observe that for VP16, pUL37 and VP1/2, changing the labelling from secondary to primary resulted in a small reduction of the diameter (by 5-10 nm). This small reduction may be a result of the heavy loading of the tegument with large labels that occurs with secondary labelling, leading to an observed swelling of the particle. The compact and rigid structure of the capsid may also contribute towards pushing the labels outwards rather than inwards.