Identification of high-affinity PB1-derived peptides with enhanced affinity to the PA protein of influenza A virus polymerase.
The influenza A virus polymerase complex, consisting of the subunits PB1, PB2, and PA, represents a promising target for the development of new antiviral drugs. We have previously demonstrated the feasibility of targeting the protein-protein interaction domain between PA and PB1 using peptides derived from the extreme N terminus of PB1 (amino acids [aa] 1 to 15), comprising the PA-binding domain of PB1. To increase the binding affinity of these peptides, we performed a systematic structure-affinity relationship analysis. Alanine and aspartic acid scans revealed that almost all amino acids in the core binding region (aa 5 to 11) are indispensable for PA binding. Using a library of immobilized peptides representing all possible single amino acid substitutions, we were able to identify amino acid positions outside the core PA-binding region (aa 1, 3, 12, 14, and 15) that are variable and can be replaced by affinity-enhancing residues. Surface plasmon resonance binding studies revealed that combination of several affinity-enhancing mutations led to an additive effect. Thus, the feasibility to enhance the PA-binding affinity presents an intriguing possibility to increase antiviral activity of the PB1-derived peptide and one step forward in the development of an antiviral drug against influenza A viruses.
Department of Virology, University of Freiburg, Freiburg, Germany.
Kerstin
K
Wunderlich
Mindaugas
M
Juozapaitis
Charlene
C
Ranadheera
Ulrich
U
Kessler
Arnold
A
Martin
Jessica
J
Eisel
Ulrike
U
Beutling
Ronald
R
Frank
Martin
M
Schwemmle
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002460:Cell Line; D006801:Humans; D009980:Influenza A virus / Q000201:enzymology* / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
C061290:PA protein, influenza viruses; D010455:Peptides; D014764:Viral Proteins; C077346:influenza virus polymerase basic protein 1; D012324:RNA-Dependent RNA Polymerase