Exuberant Immobilization of Urease on an Inorganic Support SiO2 enhancing the Enzymatic Activities by Threefold for Perennial Utilization.

Research paper by Sneha S Mondal, Susanta S Malik, Rimi R Sarkar, Dipika D Roy, Sanchari S Saha, Shailja S Mishra, Anindya A Sarkar, Mousumi M Chatterjee, Bhabatosh B Mandal

Indexed on: 20 Dec '18Published on: 20 Dec '18Published in: Bioconjugate Chemistry


Urease has been covalently immobilized on'3-D networking silica gel (SG)' using dimethyldichlorosilane (DMDCS) as second generation silane coupling reagent and m-nitroaniline as linker component in a robust methodology and subsequently characterized as [{Si(OSi)4(H2O)0.05}205.2]n=4{OSi(CH3)2-NH-C6H4-N═N-urease} 282.5H2O (molecular mass: 2,63,445 g or 263.4 kDa). Selective coupling of tyrosine residue with an identifiable 'm-nitroaniline modified SG unit' prevents enzyme-enzyme cross-linking leading to enhancement of enzymatic activity. The material worked at room temperature and its activity (luminescent and ammonia releasing efficiency) was enhanced by threefold (for both synthetic and real sample) to native enzyme values at neutral pH. Up to 30 days and 30 cycles this threefold activity remains as such but turns down gradually to native enzyme level after 60 days and 60 cycles of reuse.