5BRO

Crystal structure of modified HexB (modB)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Protease-resistant modified human beta-hexosaminidase B ameliorates symptoms in GM2 gangliosidosis model.

Kitakaze, K.Mizutani, Y.Sugiyama, E.Tasaki, C.Tsuji, D.Maita, N.Hirokawa, T.Asanuma, D.Kamiya, M.Sato, K.Setou, M.Urano, Y.Togawa, T.Otaka, A.Sakuraba, H.Itoh, K.

(2016) J.Clin.Invest. 126: 1691-1703

  • DOI: 10.1172/JCI85300

  • PubMed Abstract: 
  • GM2 gangliosidoses, including Tay-Sachs and Sandhoff diseases, are neurodegenerative lysosomal storage diseases that are caused by deficiency of β-hexosaminidase A, which comprises an αβ heterodimer. There are no effective treatments for these diseas ...

    GM2 gangliosidoses, including Tay-Sachs and Sandhoff diseases, are neurodegenerative lysosomal storage diseases that are caused by deficiency of β-hexosaminidase A, which comprises an αβ heterodimer. There are no effective treatments for these diseases; however, various strategies aimed at restoring β-hexosaminidase A have been explored. Here, we produced a modified human hexosaminidase subunit β (HexB), which we have termed mod2B, composed of homodimeric β subunits that contain amino acid sequences from the α subunit that confer GM2 ganglioside-degrading activity and protease resistance. We also developed fluorescent probes that allow visualization of endocytosis of mod2B via mannose 6-phosphate receptors and delivery of mod2B to lysosomes in GM2 gangliosidosis models. In addition, we applied imaging mass spectrometry to monitor efficacy of this approach in Sandhoff disease model mice. Following i.c.v. administration, mod2B was widely distributed and reduced accumulation of GM2, asialo-GM2, and bis(monoacylglycero)phosphate in brain regions including the hypothalamus, hippocampus, and cerebellum. Moreover, mod2B administration markedly improved motor dysfunction and a prolonged lifespan in Sandhoff disease mice. Together, the results of our study indicate that mod2B has potential for intracerebrospinal fluid enzyme replacement therapy and should be further explored as a gene therapy for GM2 gangliosidoses.


    Related Citations: 
    • Therapeutic potential of intracerebroventricular replacement of modified human beta-hexosaminidase B for GM2 gangliosidosis.
      Matsuoka, K.,Tamura, T.,Tsuji, D.,Dohzono, Y.,Kitakaze, K.,Ohno, K.,Saito, S.,Sakuraba, H.,Itoh, K.
      (2011) Mol. Ther. 19: 1017



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Beta-hexosaminidase subunit beta
A
514Homo sapiensMutation(s): 6 
Gene Names: HEXB
EC: 3.2.1.52
Find proteins for P07686 (Homo sapiens)
Go to Gene View: HEXB
Go to UniProtKB:  P07686
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMT
Query on FMT

Download SDF File 
Download CCD File 
A
FORMIC ACID
C H2 O2
BDAGIHXWWSANSR-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.187 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 126.470α = 90.00
b = 126.470β = 90.00
c = 88.310γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALAdata scaling
iMOSFLMdata reduction
MOLREPphasing
Cootmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-05-04
    Type: Initial release