Punctuated Evolution of Influenza Virus Neuraminidase (A/H1N1) under Opposing Migration and Vaccination Pressures
Figure 5
In Figure 1 the effects of the first A-B 1949-1950 vaccination-driven NA punctuation were confined to a few peaks and valleys of [MZ scale], but the C-D 2003–2009 third vaccination-driven punctuation (swine flu reversal) shown here is qualitatively different and much more complex. It involves surprising postvaccination increases in hydrophobic peaks (except in the central region 230–310), corresponding to overall globular compaction, yet there is still global smoothing, which continues the trend started by the A-B punctuation. Here the prevaccination chain profile differences are scarcely visible, but they can be resolved by calculating hydropathic roughness (17). The 2009 flattening between 210 and 300 could facilitate cleavage of sialic acid, by making its binding site in the center of HA more closely resemble a flat cutting board. These large qualitative MZ17 profile changes occur even though the overall fluctuations in (17) [see Table 2 and text] are small. In configuration space, the opposing migration and vaccination pressures have caused a very large “Lévy” jump from a deep minimum in (17) to a slightly deeper one.
