Again, it is not possible to distinguish between nickel interacting with copper and non-interacting with copper due to the small chemical shift of about 0.2 eV which would be expected for Ni alloyed with Cu.
A more recent study found two, independent, non-interacting Copper (II) binding sites in the N-terminus of αS [9].
Thiol reagents might interact with copper at the active site of PPO, leading to the loss of the activity (Benjakul et al. [2006]).
We used immobilized metal affinity chromatography (IMAC) to investigate whether huntingtin interacts with copper.
The first 171 amino acids of wild-type huntingtin, and its glutamine expanded mutant form, interacted with copper, but not iron.
Experiments revealed that N171 containing a normal (17Q) or expanded (68Q) glutamine tract interacted with copper (II), but not iron (III) or zinc (not shown).
However, human exon-1 (17Q) huntingtin (N84), which lacks histidine 98, interacted with copper (II) and eluted at 32 mM imidazole to EDTA (Figure 2D) suggesting it has a different conformation and mode of interaction with copper than N171.
To determine whether polyglutamine containing N-terminal huntingtin fragments can interact with copper, we expressed N-terminal fragments of wild-type and mutant huntingtin by in-vitro transcription-translation (IVTT) then performed IMAC experiments.
The exon-1-17Q fragmeN84(N84) also interacted with copper (II) (Figure 2D) indicating that our findings of a copper-N-terminal huntingtin interaction are relevant to the neurodegenerative phenotype of the R6/2 HD mouse which expresses exon-1 of mutant huntingtin.
In Arabidopsis, PAA1 interacts with copper chaperones and transports Cu across the plastid envelope [ 36].
OsRFPH2-14 interacted with copper methylamine oxidase (Os04g40040), jacalin-like lectin domain-containing protein (Os01g24710), profilin domain-containing protein (Os06g05880), and universal stress protein (Os05g28740).
