9H6O | pdb_00009h6o

Leishmania major ISP2 in complex with bovine alpha-chymotrypsin

• PDB DOI: https://doi.org/10.2210/pdb9H6O/pdb

• Classification: HYDROLASE
• Organism(s): Bos taurus, Leishmania major
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2024-10-24 Released: 2026-05-06 
• Deposition Author(s): Freitag-Pohl, S., Pohl, E.
• Funding Organization(s): UK Research and Innovation (UKRI)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 
  0.268 (Depositor), 0.271 (DCC) 
• R-Value Work: 
  0.219 (Depositor), 0.223 (DCC) 

Starting Model: experimental

Literature

Deciphering the Interactions of Leishmanial Serine Protease Inhibitors ISP2 and Proteases

Freitag-Pohl, S., Pohl, E.

To be published.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Hetero 4-mer - A2B2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly Evidence: gel filtration

Macromolecule Content 

• Total Structure Weight: 87.71 kDa 
• Atom Count: 5,723 
• Modeled Residue Count: 741 
• Deposited Residue Count: 806 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Chymotrypsinogen A	A [auth D], B	245	Bos taurus	Mutation(s): 0  EC: 3.4.21.1
UniProt
Find proteins for P00766 (Bos taurus) Explore P00766  Go to UniProtKB:  P00766

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Ecotin-like protein 2	C, D [auth A]	158	Leishmania major	Mutation(s): 0  Gene Names: LmjF15.0510, LmjF_15_0510
UniProt
Find proteins for Q4QFD4 (Leishmania major) Explore Q4QFD4  Go to UniProtKB:  Q4QFD4

Small Molecules

Ligands 3 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PG4	H [auth C], I [auth A]	TETRAETHYLENE GLYCOL C8 H18 O5 UWHCKJMYHZGTIT-UHFFFAOYSA-N
GOL	F [auth D]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
ACT	E [auth D], G [auth D]	ACETATE ION C2 H3 O2 QTBSBXVTEAMEQO-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free:  0.268 (Depositor), 0.271 (DCC) 
• R-Value Work:  0.219 (Depositor), 0.223 (DCC) 

Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 85.828	α = 90
b = 86.776	β = 90
c = 96.69	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
xia2	data reduction
Aimless	data scaling
PHASER	phasing

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-05-06 
Deposition Author(s): Freitag-Pohl, S., Pohl, E.

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Funding Organization	Location	Grant Number
UK Research and Innovation (UKRI)	United Kingdom	MR/P027989/1

Revision History  

• Version 1.0: 2026-05-06
  Type: Initial release