Interactions of hepatitis B core antigen and peptide inhibitors.
The core protein (HBcAg) of hepatitis B virus (HBV) has been shown to interact with the large surface antigen during HBV morphogenesis, and these interactions can be blocked by small peptides selected from either linear or constrained phage display peptide libraries. The association of HBcAg with peptide inhibitors was quantitatively evaluated by isothermal titration calorimetry. The thermodynamic data show that the interaction between HBcAg and peptide MHRSLLGRMKGA is enthalpy-driven and occurs at a 3:1 stoichiometry and dissociation constant (Kd) value of 79.4 muM. However, peptide WSFFSNI displays a higher binding affinity for HBcAg with a Kd value of 18.5 muM when compared to peptide MHRSLLGRMKGA. A combinatorial approach using chemical cross-linking and surface-enhanced laser desorption/ionization-time-of-flight-mass spectrometry shows that the Lys of peptide MHRSLLGRMKGA interacted either with D64, E77, or D78 of HBcAg.
Tang
Kah Fai
KF
Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Abdullah
Mohd Puad
MP
Yusoff
Khatijah
K
Tan
Wen Siang
WS
D000595:Amino Acid Sequence; D003432:Cross-Linking Reagents / Q000737:chemistry; D006512:Hepatitis B Core Antigens / Q000737:chemistry* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013816:Thermodynamics; D014357:Trypsin / Q000737:chemistry
D003432:Cross-Linking Reagents; D006512:Hepatitis B Core Antigens; D009842:Oligopeptides; C525464:methionyl-histidyl-arginyl-seryl-leucyl-leucyl-glycyl-arginyl-methinoyl-lysyl-glycyl-alanine; D014357:Trypsin