Cu(II) and Ni(II) Interactions with the Terminally Blocked Hexapeptide Ac-Leu-Ala-His-Tyr-Asn-Lys-amide Model of Histone H2B (80–85)
Table 4
Spectroscopic parameters of Cu(II) and Ni(II) complexes of -LAHYNK-.
Species
UV/Vis
CD
EPR
Cu(II) complexes
CuH2L (1N)
*
331 (−0.33)(b)691 (0.11)(a)
*
CuL (3N)
591 (110)
338 (−0.98)(b), (c)637 (+0.30)(a)
170
2.230
CuH-1L
(3N)
582 (94)
299 (+0.86)(c)339 (−0.68)(b)
173
2.231
637 (+0.26)(a)
CuH-2L
(4N)
528 (120)
297 (1.00)(c), 343 (−0.39)(b)
196
2.190
475 (−0.54)(a)622 (+0.39)(a)
CuH-3L (4N)
518 (140)
300 (+1.05)(c),
348 (−0.15)(b)
196
2.180
484 (−0.93)(a)614 (0.55)(a)
CuH-4L
(4N)
515 (150)
302 (+0.58)(c)346 (−0.17)(b)
196
2.180
490 (−1.30)(a)624 (0.66)(a)
Ni(II) complexes
NiH2L (1N )
*
*
—
NiHL (2N)
*
329 (+0.34)(b), (c)
—
416 (−0.94)(a)
NiH−1L
(4N)
422
(84)
336 (+0.06)(b), (c)564 (+1.08)(a)
—
416 (−1.23)(a)
NiH−2L
(4N)
434 (140)
338 (−0.03)(b), (c)514 (+1.36)(a)
—
416 (−2.23)(a)
NiH−3L (4N)
436
(130)
336 (+0.32)(b), (c)514 (+0.80)(a)
—
416 (−3.32)(a)
-d transitions of metals, , , where M =
Cu(II) or Ni(II).*These species could not be detected spectroscopically
because of their low concentrations and/or overlap with others.