Faculty Collaboration Database

Puromycin, a selective inhibitor of PSA acts as a substrate for other M1 family aminopeptidases: Biochemical and structural basis. Int J Biol Macromol 2020 Dec 15;165(Pt A):1373-1381

Date

10/13/2020

Pubmed ID

33045297

DOI

10.1016/j.ijbiomac.2020.10.035

Scopus ID

2-s2.0-85092489654 (requires institutional sign-in at Scopus site)   2 Citations

Abstract

Puromycin sensitive aminopeptidase (PSA or NPEPPS) is a M1 class aminopeptidase is selectively inhibited by the natural product puromycin, an aminonucleoside antibiotic produced by the bacterium Streptomyces alboniger. The molecular basis for this selective inhibition has not been understood well. Here, we report the basis for selectivity of puromycin using biochemical, structural and molecular modeling tools on four different M1 family enzymes including human PSA. Except for PSA, the other three enzymes were not inhibited. Instead, the peptide bond in the puromycin is hydrolyzed to O-methyl-L-tyrosine (OMT) and puromycin aminonucleoside (PAN). Neither of the hydrolyzed products, individually or together inhibit any of the four enzymes. Crystal structure of ePepN using crystals that are incubated with puromycin contained the hydrolyzed products instead of intact puromycin. On the other hand, intact puromycin molecule was observed in the crystal structure of the inactive mutant ePepN (E298A)-puromycin complex. Surprisingly, puromycin does not enter the active site of the mutant enzyme but binds near the entrance. Comparison of puromycin binding region in ePepN mutant enzyme and molecular modeling studies suggest that PSA might be inhibited by similar mode of binding there by blocking the entrance of the active site.

Author List

Reddi R, Ganji RJ, Marapaka AK, Bala SC, Yerra NV, Haque N, Addlagatta A

Author

Neshatul Haque Postdoctoral Fellow in the Mellowes Center for Genomic Sciences and Precision Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Amino Acid Sequence
Escherichia coli
Humans
Kinetics
Male
Models, Molecular
Prostate-Specific Antigen
Protein Conformation
Puromycin
Substrate Specificity