FIG 2.

Cleavage of HA subtypes. (A and B) SDS-PAGE and silver staining analyses of intact HA and HA cleaved by human recombinant KLK1 or KLK5. Lanes from the gel images were cut and spliced together with Adobe Photoshop CS 5.1 to aid in band comparison. The recombinant HAs were from H1 subtype strains A/Brisbane/59/07 (Br/59/07), A/California/07/09 (Ca/07/09), A/New Caledonia/20/99 (NC/20/99), A/Puerto Rico/8/34 (PR/8/34), and A/Solomon Island/03/06 (SI/03/06) (A) and from H3 subtype strains A/Aichi/2/68 (Ai/2/68), A/Brisbane/10/07 (Br/10/07), A/Wisconsin/67/05 (Wi/67/05), and A/Wyoming/3/03 (A/Wy/3/03) (B). (C) Efficiency of HA cleavage by KLKs. The bar graph depicts the amount of the HA1 fragment generated by KLK cleavage of all the HAs examined. The values were determined by densitometry analysis in 3 distinct silver staining experiments (means ± standard errors of the means). (D) Alignment of the sequences in the vicinity of the proteolytic cleavage site of HAs.