Immobilization of papain: A review

Abstract

Papain is a cysteine protease from papaya, with many applications due to its broad specificity. This paper reviews for first time the immobilization of papain on different supports (organic, inorganic or hybrid supports) presenting some of the features of the utilized immobilization strategies (e.g., epoxide, glutaraldehyde, genipin, glyoxyl for covalent immobilization). Special focus is placed on the preparation of magnetic biocatalysts, which will permit the simple recovery of the biocatalyst even if the medium is a suspension. Problems specific to the immobilization of proteases (e.g., steric problems when hydrolyzing large proteins) are also defined. The benefits of a proper immobilization (enzyme stabilization, widening of the operation window) are discussed, together with some artifacts that may suggest an enzyme stabilization that may be unrelated to enzyme rigidification. ; We gratefully recognize the support from the Ministerio de Ciencia e Innovación from Spanish Government (project number CTQ2017-86170-R) and CSIC for the project AEP045. The FPU fellowship (Ministerio de Educacion) for Mr. Morellon–Sterling is gratefully recognized. Dr. Tacias-Pascacio thanks the financial support from "Programa para el Desarrollo Profesional Docente" (PRODEP) from Mexican Government. ABM would like to thank Ministerio de Ciencia Innovación y Universidades and FEDER (Project RTI2018-095291-B-I00) and the Generalitat Valenciana (PROMETEOII/2018/076) for financial support.