The structure of carboxypeptidase A

The structure of carboxypeptidase Aα at 6 Å resolution has been obtained from X-ray diffraction data from native protein crystals and crystals of four isomorphous derivatives. These crystals all have space group P21 with two molecules per unit cell: a=51·41, b=59·89, c=47·19 Å, β=97°35′. Values of E, an estimated error in |FH| for each derivative (and, in parentheses, values of R=Σ‖FH(obs.)| — |FH(calc.)‖/Σ|FH(obs.)|) are 35 (0·08) for the lead...