title: Protection of enzymes from photodegradation by entrapment within alumina.
abstract: Most enzymes are highly sensitive to UV-light in all of its ranges and their activity can irreversibly drop even after a short time of exposure. Here we report a solution of this problem by using sol-gel matrices as effective protectors against this route of enzyme inactivation and denaturation. The concept presented here utilizes several modes of action: First, the entrapment within the rigid ceramic sol-gel matrix, inhibits denaturation motions, and the hydration shell around the entrapped protein provides extra protection. Second, the matrix itself - alumina in this report - absorbs UV light. And third, sol-gel materials have been shown to be quite universal in their ability to entrap small molecules, and so co-entrapment with well documented sun-screening molecules (2-hydroxybenzophenone, 2,2'-dihydroxybenzophenone, and 2,2'-dihydroxy-4-methoxybenzophenone) is an additional key protective tool. Three different enzymes as models were chosen for the experiments: carbonic anhydrase, acid phosphatase and horseradish peroxidase. All showed greatly enhanced UV (regions UV-A, UV-B, and UV-C) stabilization after entrapment within the doped sol-gel alumina matrices.
authors.affiliation: Laboratory of Solution Chemistry of Advanced Materials and Technologies, ITMO University, St. Petersburg, 197101, Russian Federation.
authors.forename: Olga E
authors.initials: OE
authors.lastname: Shapovalova
authors.affiliation: Instituto de Ciencia de Materiales de Madrid-ICMM, CSIC, 28049, Cantoblanco, Madrid, Spain. Electronic address: david.levy@icmm.csic.es.
authors.forename: David
authors.initials: D
authors.lastname: Levy
authors.affiliation: Institute of Chemistry and the Centre for Nanoscience and Nanotechnology, the Hebrew University of Jerusalem, Jerusalem, 91904, Israel. Electronic address: david.avnir@mail.huji.ac.il.
authors.forename: David
authors.initials: D
authors.lastname: Avnir
authors.affiliation: Laboratory of Solution Chemistry of Advanced Materials and Technologies, ITMO University, St. Petersburg, 197101, Russian Federation. Electronic address: vinogradoffs@mail.ru.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Vinogradov
mesh_terms: D000135:Acid Phosphatase / Q000737:chemistry / Q000378:metabolism*; D000537:Aluminum Oxide / Q000737:chemistry*; D002256:Carbonic Anhydrases / Q000737:chemistry / Q000378:metabolism*; D005782:Gels / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D044367:Phase Transition; D010782:Photolysis; D059748:Proteolysis / Q000187:drug effects* / Q000528:radiation effects*; D013473:Sunscreening Agents / Q000737:chemistry / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D005782:Gels; D013473:Sunscreening Agents; D006735:Horseradish Peroxidase; D000135:Acid Phosphatase; D002256:Carbonic Anhydrases; D000537:Aluminum Oxide
keywords: Entrapment; Enzyme; Protection; Sol-gel; UV