title: Immobilization of α-amylase onto a calix[4]arene derivative: Evaluation of its enzymatic activity.
abstract: In order to enhance the cost-effectiveness practicability of enzymes in many industries such as pharmaceutical, food, medical and some other technological processes, there is great need to immobilize them onto a solid supports. In this study, a new and efficient immobilization of α-amylase from Saccharomyces cerevisiae has been developed by using the surface functionalization of calix[4]arene as support. A glutaraldehyde-containing amino group functionalized calix[4]arene was used to immobilize α-amylase covalently. In this procedure, imide bonds are formed between amino groups on the protein and aldehyde groups on the calix[4]arene surface. The surface modified support was characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM). The effect of various preparation conditions on the immobilized α-amylase process such as immobilization time, enzyme concentration, temperature and pH were investigated. The influence of pH and temperature on the activity of free and immobilized α-amylase was also studied using starch as substrate. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized α-amylase were 25°C and 7, respectively. Compared to the free enzyme, the immobilized α-amylase retained 85% of its original activity and exhibited significant thermal stability than the free one and excellent durability.
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan.
authors.forename: Irshad Ali
authors.initials: IA
authors.lastname: Veesar
authors.affiliation: Dr. M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro 76080, Pakistan. Electronic address: imamsolangi@yahoo.com.
authors.forename: Imam Bakhsh
authors.initials: IB
authors.lastname: Solangi
authors.affiliation: National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan.
authors.forename: Shahabuddin
authors.initials: S
authors.lastname: Memon
mesh_terms: D047250:Calixarenes / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D010636:Phenols / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000378:metabolism; D013499:Surface Properties; D013696:Temperature; D000516:alpha-Amylases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D010636:Phenols; C121325:calix(4)arene; D047250:Calixarenes; D013213:Starch; D000516:alpha-Amylases; D005976:Glutaral
keywords: Calix[4]arene; Glutaraldehyde; Immobilization; Starch; α-Amylase