I have designed a fusion protein containing a motif with two cys that I want to make a disulfide bond and create a circular motif . The protein sequence also contains a cys that should not make a bond with motif's cys. After protein modeling using I-TASSER server, i could not recognize any disulfide bond with SPDBV viewer. Could anyone help me with this problem. How can I predict that the disulfide bond is created correctly?