Medizinische Mikrobiologie und Diagnose

An Immunobioinformatic Comparison of Influenza A Subtype Hemagglutinins

Abstract

Joel K Weltman

The purpose of this research is to identify nucleotide and amino acid positions are essential for the function of the HA gene and its protein products. A metric for sequence variability was hamming distance, determined for all possible inter-subtype HA sequence pairs of H1N1, H3N2 and H6N1 HA sequences in the complete NCBI HA gene datasets. Almost all (97.22%) of nucleotide positions at which the Hamming distance was zero were in the HA2 domain of the HA gene; the invariant nucleotides occupied second and first codon positions except for a tail-region encoded invariant tryptophan. In contrast with the results at the nucleotide level, the patterns of epitope distribution in the encoded HA proteins were similar except for a 25-amino acid sequence (283-307) in the HA1 region of HA H6N1. These results demonstrate the occurrence of similar organization of immunological epitopic biopatterns in influenza a hemagglutinins at the protein level, even in the face of large differences in the sequences of encoding nucleotides and encoded amino acids.