Crohn’s disease is a type of inflammatory bowel disease. The exact etiology of this disease is still unknown, but it seems, it can be caused by foul ways of living, smoking and genetics can also play a big role in it. It is scientifically proven, that N-acetylglucosamine (NAG) has tissue repairing effects[1]. The human digestive tract cells produce an enzyme called AMCase, which breaks down chitin into its oligomers, but this enzyme is only produced intracellularly, so the oligomers do not leave the cells. There are other extracellular enzymes which break down chitin oligomers into NAG. So we searched for an extracellular enzyme that can break down chitin into oligomers. We found a former iGEM team (Kyoto 2011), that designed a BioBrick (BBa_K622006), that is very similar to our needs, but unfortunately their chitinase gene did not work. We looked then for other iGEM teams which were concerned with Crohn’s disease ( ; , but we didn’t find anything useful for our own project on their websites.
Then we have discovered in a Brazilian article[2] which handled with the expression and efficient secretion of a functional chitinase from Chromobacterium violaceum in Escherichia coli. Chromobacterium violaceum (Ch. v.) has a gene that encodes an extracellular enzyme (CV2935), which converts chitin into its oligomers. This chitinase catalyzes the hydrolytic cleavage of the beta-(1-4)-glycoside bonds present in biopolymers of N-acetylglucosamine. Our aim is to use a genetically modified probiotic bacteria transformed with this chitinase gene to break down chitin into oligomers. These oligomers are expected to be digested further to NAG by the enzymes of intestinal tract cells as mRNA studies shows these cells produce NAG-ases in huge amount.