Interaction of Cu2+ with His–Val–His and of Zn2+ with His–Val–Gly–Asp, two peptides surrounding metal ions in Cu,Zn-superoxide dismutase enzyme

Branched peptide with three histidines for the promotion of CuII binding in a wide pH range – complementary potentiometric, spectroscopic and electrochemical studies

“…S1c †) 36 and are different from those observed for CuHL (L ¼ 3H). The difference between the above listed data negates the hypothesis that the N-and C-terminal backbone arms of 3H (Fig.…”

Instability of familial spongiform encephalopathy-related prion mutants

“…Figure 3B shows [22]. Analysis of Cu, Zn-superoxide dismutase showed that the pK a value of the C-terminal histidine was 6.73 [23]. Since our data showed the conformational transition of WT* started from pH 6.5 ( Fig.…”

On the possible roles of N-terminal His-rich domains of Cu,Zn SODs of some Gram-negative bacteria

“…1.). The peptide has six readily available binding sites for zinc(II) ( [27][28][29]. However, the equilibrium constant of the process Zn 2+ + H 2 L = ZnH 2 L (log K = 6.58) is higher than the related value for histamine itself (log  101 = 5.15 [30]), or those of some {3N im } and {NH 2 ,2N im } coordinated complexes (log K = 5.1 [31] and 5.94 [29], respectively), indicating that additional binding sites should be taken into consideration.…”

“…Such complexes of peptides with unprotected N-terminal histidine generally have bis-histamine {2NH 2 ,2N im } type binding [27][28][29], which provides relatively high stability (e.g. log K = 10.05 in the case of HVGD peptide [28]) .…”

“…Such complexes of peptides with unprotected N-terminal histidine generally have bis-histamine {2NH 2 ,2N im } type binding [27][28][29], which provides relatively high stability (e.g. log K = 10.05 in the case of HVGD peptide [28]) . In the present case the equilibrium constant of the analogous process Zn 2+ + 2H 2 L = Zn(H 2 L) 2 is rather similar (log K = 10.27), although considering the size difference between the two peptide, the somewhat higher log K value may suggest additional N im /COOcoordination beside the bis-histamine type binding.…”