ID   HEXL_LUPAL              Reviewed;          26 AA.
AC   B3EWR5;
DT   29-MAY-2013, integrated into UniProtKB/Swiss-Prot.
DT   13-NOV-2013, sequence version 2.
DT   25-MAY-2022, entry version 14.
DE   RecName: Full=Beta-hexosaminidase;
DE            EC=3.2.1.52;
DE   AltName: Full=Beta-GlcNAcase;
DE   AltName: Full=Beta-N-acetylhexosaminidase;
DE            Short=Beta-NAHase;
DE   AltName: Full=N-acetyl-beta-glucosaminidase;
DE   Flags: Fragment;
OS   Lupinus albus (White lupine) (Lupinus termis).
OC   Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC   Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC   rosids; fabids; Fabales; Fabaceae; Papilionoideae; 50 kb inversion clade;
OC   genistoids sensu lato; core genistoids; Genisteae; Lupinus.
OX   NCBI_TaxID=3870;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, CATALYTIC ACTIVITY, ACTIVITY REGULATION,
RP   BIOPHYSICOCHEMICAL PROPERTIES, TISSUE SPECIFICITY, DEVELOPMENTAL STAGE, AND
RP   GLYCOSYLATION.
RC   TISSUE=Cotyledon;
RX   PubMed=23602380; DOI=10.1016/j.jplph.2013.03.009;
RA   Santos C.N., Alves M., Oliveira A., Ferreira R.B.;
RT   "beta-N-Acetylhexosaminidase involvement in alpha-conglutin mobilization in
RT   Lupinus albus.";
RL   J. Plant Physiol. 170:1047-1056(2013).
CC   -!- FUNCTION: Has hexosaminidase activity. Active with both p-nitrophenyl-
CC       beta-D-N-acetylglucosamine (pNP-GlcNAc) and p-nitrophenyl-beta-D-N-
CC       acetylgalactosamine (pNP-GalNAc). Not active toward p-nitrophenyl-beta-
CC       D-N,N'-diacetylchitobiose (pNP-(GlcNAc)2) or p-nitrophenyl-beta-D-
CC       N,N',N''-triacetylchitobiose (pNP-(GlcNAc)3). Removes terminal GlcNAc
CC       and may be involved in storage protein degradation.
CC       {ECO:0000269|PubMed:23602380}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine
CC         residues in N-acetyl-beta-D-hexosaminides.; EC=3.2.1.52;
CC         Evidence={ECO:0000269|PubMed:23602380};
CC   -!- ACTIVITY REGULATION: Inhibited by AgNO(3) at a concentration of 0.1 mM.
CC       Strongly inhibited by CdCl(2), ZnCl(2) and FeCl(3) and moderately by
CC       CoCl(2), CuSO(4) and NiCl(2) at 10 mM concentration. CaCl(2), MgCl(2),
CC       MnSO(4) and KI also have a slight inhibitory effect of 20%-25% at 10 mM
CC       concentration. Activated to a small extent by MgCl(2) at 0.1 mM
CC       concentration but inhibited with increasing concentration. Not affected
CC       by carbohydrates such as fucose, galactose and glucose but displays a
CC       slight decrease in activity up to 25% with lactose, alpha-mannose and
CC       N-acetyl-galactosamine (GalNAc). {ECO:0000269|PubMed:23602380}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=2.59 mM for pNP-GlcNAc {ECO:0000269|PubMed:23602380};
CC         KM=2.94 mM for pNP-GalcNAc {ECO:0000269|PubMed:23602380};
CC         Vmax=18.4 umol/min/mg enzyme with pNP-GlcNAc as substrate
CC         {ECO:0000269|PubMed:23602380};
CC         Vmax=2.73 umol/min/mg enzyme with pNP-GalcNAc as substrate
CC         {ECO:0000269|PubMed:23602380};
CC       pH dependence:
CC         Optimum pH is 5.0 with pNP-GlcNAc and 4.0 with pNP-GalNAc. Half
CC         maximal activity observed at pH 3.0 and 6.5 with pNP-GlcNAc and at pH
CC         2.5 and 5.5 with pNP-GalNAc. Retains over 90% of its activity between
CC         pH 6.5-8.0 with pNP-GlcNAc, and between pH 6.0-7.5 with pNP-GalNAc.
CC         {ECO:0000269|PubMed:23602380};
CC       Temperature dependence:
CC         Optimum temperature is 50 degrees Celsius toward pNP-GlcNAc and 60
CC         degrees Celsius toward pNP-GalNAc. Displays activity higher than 50%
CC         between 35-70 degrees Celsius. Stable under 30 degrees Celsius.
CC         {ECO:0000269|PubMed:23602380};
CC   -!- TISSUE SPECIFICITY: Detected in dry seeds and cotyledons.
CC       {ECO:0000269|PubMed:23602380}.
CC   -!- DEVELOPMENTAL STAGE: Activity levels increase 5-9 days after imbibition
CC       in the hypocotyls and within 3-9 days in the roots. Detected in dry
CC       seeds but increased levels observed 5 days after seed imbibition.
CC       {ECO:0000269|PubMed:23602380}.
CC   -!- PTM: Glycosylated. {ECO:0000269|PubMed:23602380}.
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DR   AlphaFoldDB; B3EWR5; -.
DR   GO; GO:0004563; F:beta-N-acetylhexosaminidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0102148; F:N-acetyl-beta-D-galactosaminidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0008152; P:metabolic process; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Glycoprotein; Glycosidase; Hydrolase.
FT   PEPTIDE         1..>26
FT                   /note="Beta-hexosaminidase"
FT                   /id="PRO_0000422556"
FT   UNSURE          8
FT                   /note="E or N"
FT   NON_TER         26
SQ   SEQUENCE   26 AA;  2980 MW;  5F04E3EC26FC875D CRC64;
     VDSEDLIEAF KIYVEDDNEH LQGSVD