CHARACTERIZATION OF THE INTERACTION BETWEEN PANCREATIC TRYPSIN AND AN ENTERIC COPOLYMER AS A TOOL FOR SEVERAL BIOTECHNOLOGICAL APPLICATIONS
BRAIA, MAURICIO; LOUREIRO, DANA; TUBIO, GISELA; ROMANINI, DIANA
COLLOIDS AND SURFACES B-BIOINTERFACES
ELSEVIER SCIENCE BV
Lugar: Ontario; Año: 2015 vol. 136 p. 1217 - 1217
Protein-polyelectrolyte complexes are very interesting systems since they can be applied in many long-established and emerging areas of the biotechnology. From nanotechnology to industrial processing, these complexes are used for many purposes: to build multilayer particles for biosensors; to entrap and deliver proteins for pharmaceutical applications; to isolate and immobilize proteins.The enteric copolymer poly(methacrylic acid-co-methyl methacrylate) 1:2(MMA), has been designed for drug delivery but it presents chemical characteristics which allow use it for other applications.Understanding the interaction between trypsin and this polymer is very important in order to optimize the mechanism of formation of this complexfor different biotechnological applications.The formation of the insoluble trypsin-MMAcomplex was studied by spectroscopy and isothermal titration calorimetry. Structural analysis of trypsin was carried out by catalytic activity assays, circular dichroism and differential scanning calorimetry. ITC experiments showed that the insoluble complexcontains12 trypsin molecules per MMAmolecule at pH 5 and they interact with high affinity to form insoluble complexes. Both electrostatic and hydrophobic forces are involved in the formation of the complex. The structure of trypsin is not affected by the presence of MMA, although it interacts with some domains of trypsin affecting its thermal denaturation as seen in the DSC experiments. Its catalytic activity is not altered.Dynamic Light Scattering demonstrated the presence of an insoluble and soluble trypsin-copolymer complex at pH 5 and 8, respectively. The insoluble complex can be dissolved by low ionic strength and/or pH in order to obtain ?free? native trypsin.