Abstract
The action of carboxypeptidase on a-bromoisobutyryl-o-, -m- and -p-aminobenzoic acids was studied and a comparison was made of the cleavability of these substances with that of other halogen acyl com-pounds reported by Utsunomiya.
1. Only m- and p-compounds were split by carboxypeptidase as in the case of other halogen acyl derivatives.
2. The optimum pH lies in both cases at pH 8.4.
3. a-Bromo-isobutyryl derivatives are attacked by the enzyme with slowness as compared with other halogen acyl compounds and at nearly the same rate as a-bromo-isocapronyl derivatives.
In conclusion the authors wish to express their sincere thanks to Prof. Dr. T. Uchino for his kind suggestion throughout this work.
The expence of this research has been defrayed from the Scientific Research Ex-penditure of the Department of Education. (T. Uchino)
