<p> European Biophysics Journal</p><p>Electronic Supplementary Material</p><p>For</p><p>Folding of an All-Helical Greek-Key Protein Monitored by Quenched-Flow Hydrogen-</p><p>Deuterium Exchange and NMR Spectroscopy</p><p>Lesley H. Greene1,* · Hai Li1 · Junyan Zhong2 · Guoxia Zhao1 · Khym Wilson1</p><p>1Department of Chemistry and Biochemistry, 4541 Hampton Boulevard, Old Dominion</p><p>University, Norfolk, VA 23529, USA; 2College of Sciences Major Instrumentation Cluster, 4402</p><p>Elkhorn Avenue, Old Dominion University, Norfolk, VA 23529, USA</p><p>*To whom correspondence should be addressed: L.H. Greene, Department of Chemistry and </p><p>Biochemistry, 4541 Hampton Boulevard, Old Dominion University, Norfolk, VA 23529, USA.</p><p>E-mail: [email protected]</p><p>1</p><p>Figure S1. The HSQC spectrum of Fadd-DD in 100 mM K2HPO4/50 mM citric acid, 5 mM DTT</p><p>(pH 4.8) and 10% D2O at 30°C. The twenty-four stable amide protons in our kinetic study are indicated in bold and underlined.</p><p>2 Figure S2. Simple schematic model of protein folding for Fadd-DD based on experimental data. </p><p>The helices are denoted with numbers 1-6. The hydrophobic core is depicted by the dotted circle. Here all six helices are formed concomitant with the establishment of the hydrophobic core, however only helices 1, 2, 4 and 5 are involved in native tertiary interactions in the transition state. Helices 3 and 6 interact with the core helices on a later folding time-scale. </p><p>3</p>