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B3EWR5 (HEXL_LUPAL) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 5. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Beta-hexosaminidase

EC=3.2.1.52
Alternative name(s):
Beta-GlcNAcase
Beta-N-acetylhexosaminidase
Short name=Beta-NAHase
N-acetyl-beta-glucosaminidase
OrganismLupinus albus (White lupin) (Lupinus termis)
Taxonomic identifier3870 [NCBI]
Taxonomic lineageEukaryotaViridiplantaeStreptophytaEmbryophytaTracheophytaSpermatophytaMagnoliophytaeudicotyledonsGunneridaePentapetalaerosidsfabidsFabalesFabaceaePapilionoideaeGenisteaeLupinus

Protein attributes

Sequence length26 AA.
Sequence statusFragment.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Has hexosaminidase activity. Active with both p-nitrophenyl-beta-D-N-acetylglucosamine (pNP-GlcNAc) and p-nitrophenyl-beta-D-N-acetylgalactosamine (pNP-GalNAc). Not active toward p-nitrophenyl-beta-D-N,N'-diacetylchitobiose (pNP-(GlcNAc)2) or p-nitrophenyl-beta-D-N,N',N''-triacetylchitobiose (pNP-(GlcNAc)3). Removes terminal GlcNAc and may be involved in storage protein degradation. Ref.1 Ref.1

Catalytic activity

Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. Ref.1 Ref.1

Enzyme regulation

Inhibited by AgNO3 at a concentration of 0.1 mM. Strongly inhibited by CdCl2, ZnCl2 and FeCl3 and moderately by CoCl2, CuSO4 and NiCl2 at 10 mM concentration. CaCl2, MgCl2, MnSO4 and KI also have a slight inhibitory effect of 20%-25% at 10 mM concentration. Activated to a small extent by MgCl2 at 0.1 mM concentration but inhibited with increasing concentration. Not affected by carbohydrates such as fucose, galactose and glucose but displays a slight decrease in activity up to 25% with lactose, alpha-mannose and N-acetyl-galactosamine (GalNAc). Ref.1

Tissue specificity

Detected in dry seeds and cotyledons. Ref.1

Developmental stage

Activity levels increase 5-9 days after imbibition in the hypocotyls and within 3-9 days in the roots. Detected in dry seeds but increased levels observed 5 days after seed imbibition. Ref.1

Post-translational modification

Glycosylated. Ref.1

Biophysicochemical properties

Kinetic parameters:

KM=2.59 mM for pNP-GlcNAc Ref.1

KM=2.94 mM for pNP-GalcNAc

Vmax=18.4 µmol/min/mg enzyme with pNP-GlcNAc as substrate

Vmax=2.73 µmol/min/mg enzyme with pNP-GalcNAc as substrate

pH dependence:

Optimum pH is 5.0 with pNP-GlcNAc and 4.0 with pNP-GalNAc. Half maximal activity observed at pH 3.0 and 6.5 with pNP-GlcNAc and at pH 2.5 and 5.5 with pNP-GalNAc. Retains over 90% of its activity between pH 6.5-8.0 with pNP-GlcNAc, and between pH 6.0-7.5 with pNP-GalNAc.

Temperature dependence:

Optimum temperature is 50 degrees Celsius toward pNP-GlcNAc and 60 degrees Celsius toward pNP-GalNAc. Displays activity higher than 50% between 35-70 degrees Celsius. Stable under 30 degrees Celsius.

Ontologies

Keywords
   Molecular functionGlycosidase
Hydrolase
   PTMGlycoprotein
   Technical termDirect protein sequencing
Gene Ontology (GO)
   Molecular_functionbeta-N-acetylhexosaminidase activity

Inferred from electronic annotation. Source: UniProtKB-EC

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Peptide1 – ›26›26Beta-hexosaminidase
PRO_0000422556

Experimental info

Sequence uncertainty81E or N
Non-terminal residue261

Sequences

Sequence LengthMass (Da)Tools
B3EWR5 [UniParc].

Last modified November 13, 2013. Version 2.
Checksum: 5F04E3EC26FC875D

FASTA262,980
        10         20 
VDSEDLIEAF KIYVEDDNEH LQGSVD 

« Hide

References

[1]"beta-N-Acetylhexosaminidase involvement in alpha-conglutin mobilization in Lupinus albus."
Santos C.N., Alves M., Oliveira A., Ferreira R.B.
J. Plant Physiol. 170:1047-1056(2013) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE, FUNCTION, CATALYTIC ACTIVITY, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, TISSUE SPECIFICITY, DEVELOPMENTAL STAGE, GLYCOSYLATION.
Tissue: Cotyledon.

Cross-references

3D structure databases

ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

ProtoNetSearch...

Entry information

Entry nameHEXL_LUPAL
AccessionPrimary (citable) accession number: B3EWR5
Entry history
Integrated into UniProtKB/Swiss-Prot: May 29, 2013
Last sequence update: November 13, 2013
Last modified: February 19, 2014
This is version 5 of the entry and version 2 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programPlant Protein Annotation Program

Relevant documents

Glycosyl hydrolases

Classification of glycosyl hydrolase families and list of entries