sidechain = Group('cyx_sidechain_noh')
peptide = Group('peptide_noh')
bonds = [Bond(peptide.C_alpha, sidechain.C_beta), ]
symbol = 'Cyx'
amber_charge = {sidechain.S_gamma: -0.1081, peptide.O: -0.5679, peptide.C_alpha: 0.0429, sidechain.C_beta: -0.079, peptide.N: -0.4157, peptide.C: 0.5973, }
name = 'cystine (s-s_bridge)'
chain_links = [peptide.N, peptide.C]
