Quantification of immobilized Candida antarctica lipase B (CALB) using ICP - AES combined with Bradford Method

PAULA NICOLÁS; VERÓNICA LASSALLE; M.L.FERREIRA

ENZYME AND MICROBIAL TECHNOLOGY

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2016

0141-0229

The aim of this manuscript was to study the application of a new method of proteinquantification in Candida antarctica lipase B commercial solutions. Error sourcesassociated to the traditional Bradford technique were demonstrated. Eight biocatalystsbased on Candida antarctica lipase B (CALB) immobilized onto magnetite nanoparticleswere used. Magnetite nanoparticles were coated with chitosan (CHIT) and modified withglutaraldehyde (GLUT) and aminopropyltriethoxysilane (APTS). Later, CALB wasadsorbed on the modified support.The proposed novel protein quantification method included the determination of sulfur(from protein in CALB solution) by means of Atomic Emission by Inductive CouplingPlasma (AE-ICP). Four different protocols were applied combining AE-ICP and classicalBradford assays, besides Carbon, Hydrogen and Nitrogen (CHN) analysis. The calculatederror in protein content using the ?classic? Bradford method with bovine serum albuminas standard ranged from 400 to 1200 % when protein in CALB solution was quantified.These errors were calculated considering as ?true protein content values? the results of theamount of immobilized protein obtained with the improved method. The optimumquantification procedure involved the combination of Bradford method, ICP and CHNanalysis.