Abstract

Recently it was reported ( Hamilton, Spona, and Crowell, 1967) that pepsin was inactivated by an equimolar amount of 1-diazo-4-phenylbutanone-2 (DPB). The results indicated that the reaction occurred at or near the active site of pepsin. In the present communication we report evidence indicating that DPB reacts with pepsin to form an ester of 1-hydroxy-4-phenylbutanone-2 (HPB) with the β-carboxyl group of an aspartyl residue, and that the amino acid sequence containing this aspartyl residue is: Ile-Val-Asp-Thr. This aspartyl residue is different from that attacked by another class of pepsin inhibitors, the α-haloketones ( Erlanger, Vratsanos, Wassermann, and Cooper, 1966). Therefore, the present results define a different section of the pepsin molecule which may be involved in the enzymic catalysis.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.