Table 1. Various complex species formed at the appropriate pH (values given in brackets), determined on the basis of spectroscopic and potentiometric measurement [13] (the pH value for Cu(II)-NSAAY-NH2 4N complex was estimated on the basis of UV-Vis spectra measured in the present work).
peptide | 4N(O)- | 4N | 3N | 2N | 1N |
---|---|---|---|---|---|
AAAAA-NH2 | CuH-3L (11.0) | CuH-2L (8.0) | CuH-1L (6.5) | CuL (5.5) | |
NSFRY-NH2 | CuH-3L (11.0) | CuH-2L (9.0) | CuH-1L (6.7) | CuL (6.0) | CuHL (5.0) |
NSFRA-NH2 | - | CuH-3L (9.0) | CuH-2L (7.1) | CuH-1L (6.0) | CuL (5.0) |
NSAAY-NH2 | CuH-3L | CuH-2L (9.0) | CuH-1L | CuL | CuHL |