Dihedral angles define secondary structure Please refer to branden carl and john tooze, Introduction to protein structure 2nd ed. Garland Publishing, InC. 1999. ISBN: 0815323042Dihedral angles define secondary structure Please refer to Branden, Carl, and John Tooze. Introduction to Protein Structure. 2nd ed. Garland Publishing, Inc., 1999. ISBN: 0815323042