Structural and biochemical investigation of heptad repeat derived peptides of human SARS corona virus (hSARS-CoV) spike protein.

hSARS-CoV is the causative agent for SARS infection. Its spike glycoprotein (S) is processed by host furin enzyme to produce S1 and S2 fragments, the latter being crucial for fusion with the host membrane. This takes place via formation of a coiled coil 6-helix bundle involving N and C-terminal heptad repeat domains (HR-N and HR-C) of S2. Several fluorescent and non-fluorescent peptides from these domains were synthesized to examine their interactions by circular dichroism, thermal denaturation, native-page, mass spectrometry and fluorescence spectroscopy studies. Data revealed that HR-C domains (1153-1189), (1153-1172) and (1164-1184) all exhibit potent binding interactions with HR-N(892-931) domain. These peptides may find useful therapeutic applications in SARS intervention.