3L33

Human mesotrypsin complexed with amyloid precursor protein inhibitor(APPI)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.48 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.198 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history. 


Literature

Determinants of affinity and proteolytic stability in interactions of Kunitz family protease inhibitors with mesotrypsin.

Salameh, M.A., Soares, A.S., Navaneetham, D., Sinha, D., Walsh, P.N., Radisky, E.S.

(2010) J Biol Chem 285: 36884-36896

  • DOI: 10.1074/jbc.M110.171348
  • Primary Citation of Related Structures:  
    3L33, 3L3T

  • PubMed Abstract: 

    • An important functional property of protein protease inhibitors is their stability to proteolysis. Mesotrypsin is a human trypsin that has been implicated in the proteolytic inactivation of several protein protease inhibitors. We have found that bovine pancreatic trypsin inhibitor (BPTI), a Kunitz protease inhibitor, inhibits mesotrypsin very weakly and is slowly proteolyzed, whereas, despite close sequence and structural homology, the Kunitz protease inhibitor domain of the amyloid precursor protein (APPI) binds to mesotrypsin 100 times more tightly and is cleaved 300 times more rapidly ...

    An important functional property of protein protease inhibitors is their stability to proteolysis. Mesotrypsin is a human trypsin that has been implicated in the proteolytic inactivation of several protein protease inhibitors. We have found that bovine pancreatic trypsin inhibitor (BPTI), a Kunitz protease inhibitor, inhibits mesotrypsin very weakly and is slowly proteolyzed, whereas, despite close sequence and structural homology, the Kunitz protease inhibitor domain of the amyloid precursor protein (APPI) binds to mesotrypsin 100 times more tightly and is cleaved 300 times more rapidly. To define features responsible for these differences, we have assessed the binding and cleavage by mesotrypsin of APPI and BPTI reciprocally mutated at two nonidentical residues that make direct contact with the enzyme. We find that Arg at P(1) (versus Lys) favors both tighter binding and more rapid cleavage, whereas Met (versus Arg) at P'(2) favors tighter binding but has minimal effect on cleavage. Surprisingly, we find that the APPI scaffold greatly enhances proteolytic cleavage rates, independently of the binding loop. We draw thermodynamic additivity cycles analyzing the interdependence of P(1) and P'(2) substitutions and scaffold differences, finding multiple instances in which the contributions of these features are nonadditive. We also report the crystal structure of the mesotrypsin·APPI complex, in which we find that the binding loop of APPI displays evidence of increased mobility compared with BPTI. Our data suggest that the enhanced vulnerability of APPI to mesotrypsin cleavage may derive from sequence differences in the scaffold that propagate increased flexibility and mobility to the binding loop.

    Organizational Affiliation: 

    Department of Cancer Biology, Mayo Clinic Cancer Center, Jacksonville, Florida 32224, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Trypsin-3 A, B, C, D224Homo sapiensMutation(s): 2 
Gene Names: PRSS3, PRSS4, TRY3, TRY4
EC: 3.4.21.4
Find proteins for P35030 (Homo sapiens)
Explore P35030 
Go to UniProtKB:  P35030
NIH Common Fund Data Resources
PHAROS:  P35030
GTEx:  ENSG00000010438
Protein Feature View
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  • Reference Sequence
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Amyloid beta A4 protein E, F, G, H52Homo sapiensMutation(s): 0 
Gene Names: APP, A4, AD1
Find proteins for P05067 (Homo sapiens)
Explore P05067 
Go to UniProtKB:  P05067
NIH Common Fund Data Resources
PHAROS:  P05067
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.48 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.198 
  • Space Group: P 2 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 92.793α = 90
b = 130.067β = 90
c = 132.338γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-09-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance