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. Hydrolysis of terminal non-reducing N-acetyl-D-hexosamine residues in N-acetyl-beta-D-hexosaminides. Inhibited by AgNO(3) at a concentration of 0.1 mM. Strongly inhibited by CdCl(2), ZnCl(2) and FeCl(3) and moderately by CoCl(2), CuSO(4) and NiCl(2) at 10 mM concentration. CaCl(2), MgCl(2), MnSO(4) and KI also have a slight inhibitory effect of 20%-25% at 10 mM concentration. Activated to a small extent by MgCl(2) 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). 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. 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. Detected in dry seeds and cotyledons. 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. Glycosylated.