Based on the information provided, diagram the topography of protein C in a lipid bilayer.

1. Fig. 1 Hydrophobicity threshold 1 0 -1 Transfer DG (oil  H2O) 10 20 30 40 50 60 70 80 90 100 110 Amino acid residue 1 30 42 50 70 120 C N a1 a2 1. Protein C has been purified and sequenced. It’s association with lipid bilayer membranes is disrupted only upon dissolution of the bilayer structure with detergents. •The hydropathy plot for this protein is shown in Fig. 1. • The putative membrane intercalating domain has been identified using the photolabel [125I]-TID protease digestion of the native enzyme bound to lipid vesicles, and sequencing of isolated labeled fragments. The protease sites are indicated by the arrows in the diagram below. TID labels 2 fragments (a1 and a2) from the middle portion of the protein. Circular dichroism analysis of fragments a1 and a2 bound to vesicles suggest a strong preference for -helical secondary structure. • Single cysteine variants are engineered; one near the N-terminus (C4), one near the C-terminus (C116) , and several within the a1 and a2 segments. Each variant is expressed, purified, reconstituted into lipid vesicles, and reacted with MTS-TEMPO. The accessibility of the spin- labeled cysteines to CROX (chromium oxalate) vs O2 was tested by ESR analysis of spin exchange rates. The results are shown in Fig. 2. Fig. 2 C56 C52 C60 C33 C67 C37 Accessibility to O2 C39 C34 C116 C4 Accessibility to CROX • Protein C is a resident of the plasma membrane. The reactivity towards antibodies specific for the N-terminal 15 amino acids or the C-terminal 15 amino acids of native protein C in plasma membranes was tested. Reaction with anti-N-terminal antibody is positive, with or without detergent lysis of the cell membrane, but reaction with anti-C-terminal antibody is positive only after detergent lysis. Based on the information provided, diagram the topography of protein C in a lipid bilayer.