1. A Second Look at Mini-Protein Stability: Analysis of FSD-1 Using Circular Dichroism, Differential Scanning Calorimetry, and Simulations 
Jianwen A. Feng, Jeff Kao, Garland R. Marshall 
Biophysical Journal 
Volume 97, Issue 10, Pages (November 2009)
DOI: /j.bpj
Copyright © 2009 Biophysical Society Terms and Conditions

2. Figure 1
Structure of FSD-1 (PDB: 1FSD). (A) For clarity, side chains of selected residues are shown. (B) The main-chain atoms in the β-hairpin of FSD-1 are shown colors and the hydrogen bonds between Y3 and F12 highlighted by black dashes. The α-helix is shown in light gray. Figures were generated using PyMOL (33). Sequence: QQYTAKIKGRTFRNEKELRDFIEKFKGR.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2009 Biophysical Society Terms and Conditions

3. Figure 2
(A) Far-UV CD spectra of FSD-1 at 4°C and 80°C. Spectra were measured at 4°C premelting (solid) and postmelting (dotted). (B) Spectra of FSD-1 and an unfolded FSD-1 double mutant (I7PKDP) at 4°C. DP denotes D-Proline.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2009 Biophysical Society Terms and Conditions

4. Figure 3
Thermal unfolding of FSD-1 monitored by CD at 218 nm. The melting curve was fitted to a two-state model and the resulting Tm was 41°C and ΔHvH was 18 kcal/mol.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2009 Biophysical Society Terms and Conditions

5. Figure 4
DSC melting curve fitted to a two-state model. Tm was determined to be 41°C and ΔHcal was determined to be 15 kcal/mol. Dark and gray circles represent two back-to-back DSC scans.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2009 Biophysical Society Terms and Conditions

6. Figure 5
Potential-energy overlap between neighboring replicas during the last 10 ns of the simulation. Each distribution curve represents the potential-energy distribution at a single temperature. The left-most curve represents the potential energy of the lowest-temperature replica, and the right-most curve represents the potential energy of the highest-temperature replica.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2009 Biophysical Society Terms and Conditions

7. Figure 6
(Top) Temperatures sampled by 3 of 64 representative replicas during the course of the simulation. Replicas 1, 31, and 62 started at K, K, and K, respectively. (Bottom) RMSD of three replicas during the course of the REMD simulation. A folding event is observed in replica 62, and unfolding events are observed in replicas 1 and 31.
Biophysical Journal  , DOI: ( /j.bpj )
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8. Figure 7
Thermal unfolding monitored by RMSD and RMSF. The data were fit to a two-state model. RMSF values were calculated for residues 3–25. The fitted melting temperatures Tm are shown in the panels.
Biophysical Journal  , DOI: ( /j.bpj )
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9. Figure 8
Average number of hydrogen bonds formed between main-chain atoms in residues Y3 and F12 (x) or between residues in strand 1 (residues 2–6) and strand 2 (residues 9–13) of the hairpin (+) during the REMD simulation.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2009 Biophysical Society Terms and Conditions