9FN8 | pdb_00009fn8

Crystal structure of human carboanhydrase XII with 4-benzyl-5,7,8-trifluoro-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-sulfonamide 1,1-dioxide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.21 Å
  • R-Value Free: 
    0.170 (Depositor), 0.168 (DCC) 
  • R-Value Work: 
    0.136 (Depositor), 0.140 (DCC) 
  • R-Value Observed: 
    0.140 (Depositor) 

Starting Model: experimental
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Literature

Design of Rigid Compounds to Enhance Selectivity for Carbonic Anhydrase IX.

Vaskevicius, A.Trumpickaite, G.Parafjanovic, E.Manakova, E.Mickeviciute, A.Gedgaudas, M.Kojis, T.Paketuryte-Latve, V.Smirnov, A.Baranauskiene, L.Grazulis, S.Zubriene, A.Dudutiene, V.Matulis, D.

(2025) Chemistry 31: e202404409-e202404409

  • DOI: https://doi.org/10.1002/chem.202404409
  • Primary Citation of Related Structures:  
    9FJQ, 9FJV, 9FN7, 9FN8

  • PubMed Abstract: 

    High affinity and selectivity for intended targets is an important goal of small molecule design in drug discovery, yet balancing molecular flexibility and rigidity remains a challenge. While flexible compounds can increase target affinity, they often result in non-specific interactions and reduced selectivity. In contrast, rigid compounds may recognize their target more precisely and have lower off-target effects. In this study, we incorporated a 1,1-dioxido-1,4-thiazine ring into fluorinated benzenesulfonamide derivatives with bulky meta-substituents to enhance selectivity for human carbonic anhydrase IX (CAIX), an important cancer-associated target. Due to the structural similarities of CAIX with other carbonic anhydrase isozymes, selective inhibition remains a significant challenge. A series of 3,4-substituted trifluorobenzenesulfonamides containing oxidized thiazine rings were synthesized using a novel synthetic pathway. Although the potency against CAIX was modestly reduced compared to more flexible analogs, selectivity increased significantly, with lead compounds 7 d and 7 e exhibiting over 1000-fold selectivity for CAIX over most other isozymes. X-ray crystallography revealed the structural basis for this selectivity, confirming the advantageous positioning of rigidified compounds within some CA isozyme active sites. These findings highlight the potential of molecular rigidity in the design of highly selective inhibitors for therapeutic applications.


  • Organizational Affiliation

    Department of Biothermodynamics and Drug Design, Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio 7, Vilnius, LT-10257, Lithuania.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Carbonic anhydrase 12
A, B, C, D
263Homo sapiensMutation(s): 0 
Gene Names: CA12
EC: 4.2.1.1
UniProt & NIH Common Fund Data Resources
Find proteins for O43570 (Homo sapiens)
Explore O43570 
Go to UniProtKB:  O43570
PHAROS:  O43570
GTEx:  ENSG00000074410 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO43570
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
A1IDL (Subject of Investigation/LOI)
Query on A1IDL

Download Ideal Coordinates CCD File 
M [auth A],
P [auth B],
T [auth C],
Y [auth D]
5,7,8-tris(fluoranyl)-1,1-bis(oxidanylidene)-4-(phenylmethyl)-2,3-dihydro-1$l^{6},4-benzothiazine-6-sulfonamide
C15 H13 F3 N2 O4 S2
JRBPZWOABQWAHK-UHFFFAOYSA-N
DMS
Query on DMS

Download Ideal Coordinates CCD File 
Z [auth D]DIMETHYL SULFOXIDE
C2 H6 O S
IAZDPXIOMUYVGZ-UHFFFAOYSA-N
ZN
Query on ZN

Download Ideal Coordinates CCD File 
E [auth A],
N [auth B],
Q [auth C],
U [auth D]
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
EDO
Query on EDO

Download Ideal Coordinates CCD File 
F [auth A]
G [auth A]
H [auth A]
I [auth A]
J [auth A]
F [auth A],
G [auth A],
H [auth A],
I [auth A],
J [auth A],
K [auth A],
L [auth A],
O [auth B],
R [auth C],
S [auth C],
V [auth D],
W [auth D],
X [auth D]
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.21 Å
  • R-Value Free:  0.170 (Depositor), 0.168 (DCC) 
  • R-Value Work:  0.136 (Depositor), 0.140 (DCC) 
  • R-Value Observed: 0.140 (Depositor) 
Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.522α = 90
b = 74.084β = 108.84
c = 91.838γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
iNEXT-DiscoveryEuropean Union871037

Revision History  (Full details and data files)

  • Version 1.0: 2025-05-14
    Type: Initial release