Insights from modeling the 3D structure of H5N1 influenza virus neuraminidase and its binding interactions with ligands.
The highly pathogenic H5N1 influenza virus, which is rapidly mutating and becoming increasingly drug-resistant, was investigated by means of structure-activity relationship between NA (neuraminidase) and three inhibitors, i.e., DANA (2,3-didehydro-2-deoxy-N-acetylneuraminic acid), zanamivir, and oseltamivir. A homology model of the H5N1-NA from the highly pathogenic chicken H5N1 A viruses isolated during the 2003-2004 influenza outbreaks in Japan was built based on the crystal structure of N9-NA complexed with DANA (PDB code: 1F8B). It was found that the traditional constituent residues around the active site of NA family are highly conserved in the H5N1-NA. However, a partially lipophilic pocket composed by Ala248 and Thr249 in N9-NA becomes a hydrophilic pocket because the two residues in the H5N1-NA are replaced by hydrophilic residues Ser227 and Asn228, respectively. On the other hand, two hydrophilic residues Asn347 and Asn348 in the N9-NA are replaced by two lipophilic residues Ala323 and Tyr324 in the H5N1-NA, respectively, leading to the formation of a new lipophilic pocket. This kind of subtle variation not only destroys the original lipophilic environment but also changes the complement interaction between the H5N1-NA and DANA. Such a finding might provide insights into the secret why some of H5N1 strains bear high resistance for existing NA inhibitors, and stimulate new strategies for designing new drugs against these viruses.
Wei
Dong-Qing
DQ
College of Life Science and Technology, Shanghai Jiaotong University, 800 Dongchuan Road, Minhang District, Shanghai 200240, China.
Du
Qi-Shi
QS
Sun
Hao
H
Chou
Kuo-Chen
KC
D000081:Acetamides / Q000737:chemistry*; D001665:Binding Sites; D003198:Computer Simulation; D004789:Enzyme Activation; D006146:Guanidines / Q000737:chemistry*; D053124:Influenza A Virus, H5N1 Subtype / Q000201:enzymology*; D008956:Models, Chemical; D008958:Models, Molecular; D019158:N-Acetylneuraminic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D009439:Neuraminidase / Q000737:chemistry*; D053139:Oseltamivir; D011485:Protein Binding; D011487:Protein Conformation; D011714:Pyrans / Q000737:chemistry*; D020539:Sequence Analysis, Protein / Q000379:methods; D012794:Sialic Acids / Q000737:chemistry*; D013329:Structure-Activity Relationship; D053243:Zanamivir
D000081:Acetamides; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; D053139:Oseltamivir; C036137:2-deoxy-2,3-dehydro-N-acetylneuraminic acid; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid; D053243:Zanamivir