Skip to content
2000
Volume 10, Issue 2
  • ISSN: 1573-4080
  • E-ISSN: 1875-6662

Abstract

Dextransucrase isolated from Weissella cibaria JAG8 was subjected to active site mapping analysis by using lysine specific inhibitor viz. pyridoxal-5’-phosphate (PLP) and 2,4,6-trinitrobenzenesulphonic acid (TNBS) gave 98.5% and 98.7% inhibition in enzyme activity at 25 mM concentration respectively. The -NH2 lysine derivative of enzymeinhibitor complex with PLP and TNBS gave absorbance maxima at 325 and 369 nm, respectively. PLP modified dextransucrase on reduction with sodium borohydride led to the formation of N-phosphopyridoxyl lysine complex showed fluorescence maxima at 397 nm indicating that one or more lysine residues present near or at the active site and are essential for enzyme activity. Sucrose, provided protection to the enzyme against inactivation by PLP. The enzyme inactivation caused by cysteine specific inhibitors, DTNB (10 mM) and iodoacetic acid (25 mM) was 98.7% and 98.9%, respectively. Enzyme-inhibitor complexes with DTNB (thio-nitrobenzoate) and iodoacetic acid (thio-acetate) were confirmed by appearance of absorbance maxima at 406 and 323 nm, respectively. These results showed that one or more cysteine residues present near or at the active site and are essential for enzyme activity. Essential cysteine residue at the active site is reported for the first time in dextransucrase.

Loading

Article metrics loading...

/content/journals/cei/10.2174/1573408009999131231110557
2014-09-01
2025-07-10
Loading full text...

Full text loading...

/content/journals/cei/10.2174/1573408009999131231110557
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error
Please enter a valid_number test