Purification and some properties of ?-N-acetyl-D-glucosaminidase from prawn (Penaeus vannamei)

Digestive enzymes of two brachyuran and two anomuran land crabs from Christmas Island, Indian Ocean

“…Mass spec indicates that the mass of the enzyme was determined by its mass spectrum on a time of flight mass spectrometer. cDna indicates the size of the enzyme predicted from the translated amino acid sequence -acetyl-β-d-glucosaminidase Penaeus vannamei (prawn) 105 (2 × 45 subunits) (denatured) Xie et al (2004) Scylla serrata (crab) 132 (2 × 65.8 subunits) (denatured) Zhang et al (2006) Penaeus japonicus (prawn) 37 (denatured), 57 (mass spec) Kono et al (1990) endo-β-1,4-glucanase Cherax quadricarinatus 30, 40 (native) Xue et al (1999) (2010) terrestrial, mainly leaf litter diet, particularly in the gecarcinids, G. natalis and D. celeste since these species possess isozymes that were not observed in the coenobitids. In particular, the gecarcinid crabs possessed additional endo-β-1,4-glucanase isozymes: G. natalis possessed two extra isoforms and D. celeste one.…”

Isolation, Purification, and Biochemical Characterization of Two Forms of Lysosomal β-N-Acetylhexosaminidase from the InvertebrateUnio

“…7A). The effect of temperature on the activity of the two enzymes was studied by incubating the enzymes with substrates at increasing temperatures, from 10 C to 100 C, under the reaction conditions described above under Materials and Methods. Both enzymes showed maximum activity at 70 C (Fig.…”

Studies on the Chemical Modification of the Essential Groups of N-Acetyl-β-d-Glucosaminidase from Viscera of Green Crab (Scylla Serrata)

“…However, the disulfide bond and carbamidine groups of arginine residue were unrelated to the enzyme-catalyzing function. All previous research on NAGase from different species unanimously agreed that the carboxyl residue of aspartic acid or glutamic acid was involved in the active site of the enzyme [10][11][12]. Both Lin and Amutha reported that the histidine and tryptophan residue were essential groups for NAGase activity, respectively [9,11].…”

“…Chitinases have been well investigated in some insects [2], bacteria [3], and plants [4] for their important roles in molting, digestion of chitinous foods, and defense systems against parasites. Meanwhile, chitinases have been characterized and reported in marine invertebrates, molluscs, and crustaceans about their purification, concentrations in different growth stage, and distribution in different organs, such as oysters [5], prawns [6], lobsters [7], krills [8], topshell (Turbo cornutus) [9], and prawn (Penaeus vannamei) [10]. However, the knowledge about functional groups and catalytic mechanism of NAGase are yet limited.…”