Abstract: The HPcoarse-grained model has been applied to study three-dimensional spatial structures of a protein via lattice Monte Carlo simulation, in which residues exhibit different hydropathical energies.Reversed HPmodel has also been introduced to deal with protein under a lipid environment.The simulation approach seems very efficient.Preliminary computer experiment has been performed to study E-protein which is believed in the envelope of SARS(Severe Acute Respiratory Syndrome) associated coronavirus.Coil-globule transition has been reproduced in E-protein under a completely aqueous or lipid environment.Heterogeneity of this 76-residue polypeptide is verified to be important.Aqueous environment results in a hydrophobic core and hydrophilic loops.In contrast, lipid environment makes central segment as bridge or loop linking two relatively hydrophilic marginal segments.

Key words: Protein folding, Computer simulation, Macromolecular conformation statistics, SARS coronavirus, Bioinformatics