Activation and stabilization of asparaginase by anti‐asparaginase IgG and its Fab

Abstract

Modified asparaginase, in which 4 tryptophan residues were modified with 2-hydroxy-S-nitrobenzyl bromide, had little enzymic activity and retained immunoreactivity ((1976) FEBS Lett. 65, 11-t 51. Addition of IgG or its Fab towards asparaginase to the modified asparaginase gave rise to marked enhancement of the enzymic activity. Native asparaginase (4 subunits) lost the enzymic activity due to dissociation into subunits by dilution of the enzyme solution. However. in the presence of Fab, asparaginase did not lose enzymic activity on dilution, probably due to no dissociation into subunits occurring.

Characterization and immobilization of purified Aspergillus flavipesl-methioninase: continuous production of methanethiol

“…The activity of chitin enzyme was increased by 1AE4-fold using 4AE0% glutaraldehyde as spacer, to the control (2AE5%), assuming the stable multipoint covalent bonds between the enzyme and chitin via glutaraldehyde, stabilizing the enzyme conformation structure and increasing the local surface area of the carrier (Yoshimoto et al 1985), thus reducing the steric hindrance around enzyme active site (Siso et al 1990 andAbdel-Naby et al 1998). In contrary, a significant reduction in enzyme activity was observed at higher levels of spacer that may be ascribed to denaturing ⁄ dissociating effect of the enzyme tertiary structure.…”

“…The activity of chitin enzyme was increased by 1·4‐fold using 4·0% glutaraldehyde as spacer, to the control (2·5%), assuming the stable multipoint covalent bonds between the enzyme and chitin via glutaraldehyde, stabilizing the enzyme conformation structure and increasing the local surface area of the carrier (Yoshimoto et al. 1985), thus reducing the steric hindrance around enzyme active site (Siso et al.…”

Polymer–protein conjugates: an enzymatic activity perspective

“…This holds particularly true for enzymes composed of multiple subunits, such as ASNase, and whose enzymatic activity is lost due to dissociation into inactive subunits through dilution. 71 Consequently, and as highlighted in this section, multi-point attachment has the potential to increase the thermal stability of the conjugate because of its preventative effect on protein denaturation as well as to affect the pH-activity profiles of the conjugate because of the change in the microenvironment surrounding the enzyme.…”

L-Ασπαραγιναση Του Πρωτοζωου Tetrahymena Pyriformis: Δομη Ρυθμιση Της Ενζυμικης Δραστικοτητας Και Επιδραση Της Στον Πολλαπλασιασμο Καρκινικων Κυτταρων

“…Η χρήση του κλάσματος IgG και του κομματιού Fab από τον αντιορο L-ασπαραγινάσης της Ε . e ο 1 i έχει ως αποτέλεσμα την προστασία της τεταρτοταγούς διαμόρφωσης του ενζύμου (46). Η L-ασπαραγινάση που έχει απομονωθεί από διάφορες πηγές έ χει ισοηλεκτρικό σημείο στην όξινη περιοχή, από 3,6 μέχρι 6,97.…”