Sandbox Reserved 1096: Difference between revisions
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==='''Catalysis of deimination'''=== | ==='''Catalysis of deimination'''=== | ||
As mentioned before, PAD2 is a calcium-dependent enzyme which catalyzes the deimination. This reaction occurs only if calcium ions bind to specific sites of PAD2 but they don’t directly participate in catalysis : they are cofactors only. Once bonds with calcium have been formed, a '''''catalytic cysteine residue in position 647''''' in the peptidic chain changes its position to | As mentioned before, PAD2 is a calcium-dependent enzyme which catalyzes the deimination. This reaction occurs only if calcium ions bind to specific sites of PAD2 but they don’t directly participate in catalysis : they are cofactors only. Once bonds with calcium have been formed, a '''''catalytic cysteine residue in position 647''''' in the peptidic chain changes its position to carry out a [https://en.wikipedia.org/wiki/Nucleophilic_substitution nucleophilic attack] on guanidium groups of arginine residues. | ||
These arginine residues that are substrates in this reaction can bind to PAD2 because calcium binding engenders a move out of the active site for an arginin in position 347 and a move in for a tryptophan in position 348, in order to form a pocket for the substrate<ref name="ART1" />. | These arginine residues that are substrates in this reaction can bind to PAD2 because calcium binding engenders a move out of the active site for an arginin in position 347 and a move in for a tryptophan in position 348, in order to form a pocket for the substrate<ref name="ART1" />. | ||
