1. Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 Center Drive, Bethesda, Maryland 20892, Center for Vascular and Inflammatory Diseases and Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 800 West Baltimore Street, Baltimore, Maryland 21201, and Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157