Cellulose is the most common organic molecule on earth and is widely used in the textile industry. We at iGEM Toulouse-INSA-UPS 2018 are convinced that functionalising cellulose paves the way towards a whole range of exciting possibilities. From conductive paper to anti-infection tissues, applications domains are aplenty (medicine, textile, stationery, etc). The major bottleneck is the complexity to conjugate bioactive molecules to cellulose.
To circumvent this limitation and enable a wide range of chemicals to be fixated to cellulose, we designed a three headed linker protein named Cerberus (in reference to the mythological dog). Cerberus is based on the fusion of three fixating protein structures representing the three heads of the system. The first head is a protein domain of the type 3 Carbohydrates Binding Modules (CBM3) family to bind cellulose. The second is one of the strongest linkage systems of the living realm, streptavidin, with its high affinity for biotinylated compounds. The last of the heads features a non-natural amino acid, azidophenylalanine, catalysing covalent bonds by click chemistry. The versatility of our thought-out linker will allow a large variety of organic and inorganic molecules to conjugate with cellulose. During our summer, we will produce the linker and prove its large functionality by creating fluorescent, magnetic, antibiotic or even conductive cellulose in vivo using biotechnology strategies.