4AX4

PROLYL OLIGOPEPTIDASE FROM PORCINE BRAIN, H680A MUTANT

Summary for 4AX4

• Entry DOI: 10.2210/pdb4ax4/pdb
• Related: 1E5T 1E8M 1E8N 1H2W 1H2X 1H2Y 1H2Z 1O6F 1O6G 1QFM 1QFS 1UOO 1UOP 1UOQ 1VZ2 1VZ3 2XDW 4AMY 4AMZ 4AN0 4AN1
• Descriptor: PROLYL OLIGOPEPTIDASE, GLYCEROL (3 entities in total)
• Functional Keywords: hydrolase, amnesia, alpha/beta-hydrolase, beta-propeller, serine protease
• Biological source: SUS SCROFA (PIG)
• Cellular location: Cytoplasm: P23687
• Total number of polymer chains: 1
• Total formula weight: 81626.12

Authors

Szeltner, Z.,Juhasz, T.,Szamosi, I.,Rea, D.,Fulop, V.,Modos, K.,Juliano, L.,Polgar, L. (deposition date: 2012-06-08, release date: 2012-09-26, Last modification date: 2023-12-20)

Primary citation

Szeltner, Z.,Juhasz, T.,Szamosi, I.,Rea, D.,Fulop, V.,Modos, K.,Juliano, L.,Polgar, L.
The Loops Facing the Active Site of Prolyl Oligopeptidase are Crucial Components in Substrate Gating and Specificity.
Biochim.Biophys.Acta, 1834:98-, 2012

PubMed Abstract: Prolyl oligopeptidase (POP) has emerged as a drug target for neurological diseases. A flexible loop structure comprising loop A (res. 189-209) and loop B (res. 577-608) at the domain interface is implicated in substrate entry to the active site. Here we determined kinetic and structural properties of POP with mutations in loop A, loop B, and in two additional flexible loops (the catalytic His loop, propeller Asp/Glu loop). POP lacking loop A proved to be an inefficient enzyme, as did POP with a mutation in loop B (T590C). Both variants displayed an altered substrate preference profile, with reduced ligand binding capacity. Conversely, the T202C mutation increased the flexibility of loop A, enhancing the catalytic efficiency beyond that of the native enzyme. The T590C mutation in loop B increased the preference for shorter peptides, indicating a role in substrate gating. Loop A and the His loop are disordered in the H680A mutant crystal structure, as seen in previous bacterial POP structures, implying coordinated structural dynamics of these loops. Unlike native POP, variants with a malfunctioning loop A were not inhibited by a 17-mer peptide that may bind non-productively to an exosite involving loop A. Biophysical studies suggest a predominantly closed resting state for POP with higher flexibility at the physiological temperature. The flexible loop A, loop B and His loop system at the active site is the main regulator of substrate gating and specificity and represents a new inhibitor target.

PubMed: 22940581
DOI: 10.1016/J.BBAPAP.2012.08.012

Experimental method

X-RAY DIFFRACTION (1.6 Å)