The meaning of PCA

Jim Pitts (
Mon, 18 Mar 1996 16:48:14 GMT

Dear all,

PCA stands for L-2-Pyrrolidone-5- Carboxylix acid,

which is another way of saying

L-Pyroglutamic Acid (Is the light appearing?)

which is a cyclic form of L-Glutamic Acid,

which is a post-translational modification that

can occur when proteins are expressed in recombinant

DNA systems e.g. E.coli, and cause serious grief when

attempting to undertake N-terminal sequencing.

Today I would use "PYR" instead of "PCA" but

Brookhaven continue to use the latter.

This is effectively an N-terminal proline]

incorporating the NH3 in to the ring, hence

the sequencing problem.

Question: What has happened to the

two carbon atoms (gamma and delta)

required to form the ring?

Jim Pitts.