Carboxypeptidase Q is an enzyme that in humans is encoded by the CPQ gene. This is a carboxypeptidase enzyme which breaks down dipeptides (pairs of bound amino acids) into separate amino acids. It is mostly found in blood plasma, and may involved separating out the thyroid hormone, thyroxine (T4), from its precursor, thyroglobulin.
Function This gene encodes a metallopeptidase that belongs to the peptidase M28 family. The encoded protein may catalyze the cleavage of dipeptides with unsubstituted terminals into amino acids. It has also been found as protein marker for migrasomes, a type of extracellular vesicle released by migrating cells, though its role in these vesicles, if any, remains unclear.
Other names This enzyme has previously also been called "plasma glutamate carboxypeptidase" (PGCP), "Ser-Met dipeptidase", and "lysosomal dipeptidase" (LDP).
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