4 4 dianilino 1 1 binaphthyl 5 5 disulfonic acid bis ans

All 9-fluorenylmethyloxycarbonyl (Fmoc)-labeled amino acids and resin-bound amino acids were purchased from Watanabe Kagaku (Hiroshima, Japan). Piperidine for eliminating Fmoc during peptide synthesis was purchased from Tokyo Chemical Industry (Tokyo, Japan). N-Methylmorpholine and 1, 2-ethanedithiol were purchased from Nacalai Tesque (Kyoto, Japan). HPLC-grade acetonitrile, N, N-dimethylformamide, diethyl ether, trifluoroacetic acid, thioflavin T, and 4,4′-dianilino-1,1′-binaphthyl-5,5′-disulfonic acid (Bis-ANS) were purchased from Sigma Aldrich (St. Louis, MO, USA). Recombinant human protein-L-isoaspartate O-methyltransferase was purchased from NKMAX (Seongnam-si, Republic of Korea). All other analytical chemicals were purchased from FUJIFILM Wako Pure Chemical Industries (Osaka, Japan).

Sphingomonas sp. PAMC 26621 was provided by the Polar and Alpine Microbial Collection of the Korea Polar Research Institute (Incheon, South Korea) [18 (link)]. The pET28 expression vector was purchased from Novagen (Madison, WI, USA). The TA vector, restriction enzymes, and pfu polymerase were acquired from Enzynomics (Daejeon, South Korea). HisTrap, Capto Q, HiPrep desalting 26/10, Superdex 200 10/300 GL, and Superdex 200 prep grade XK16 columns were purchased from GE Healthcare (Piscataway, NJ, USA). 4,4′-Dianilino-1,1′-binaphthyl-5,5′-disulfonic acid (bis-ANS) was purchased from Sigma (St. Louis, MO, USA). All other chemical reagents were purchased from Sigma or Tokyo Chemical Industry (Tokyo, Japan).