PhD ceremony Ms. J. Ćirić: Improved characterization techniques for branched polysaccharides
|When:||Fr 16-05-2014 at 14:30|
|Where:||Doopsgezinde Kerk, Oude Boteringestraat 33, Groningen|
PhD ceremony: Ms. J. Ćirić
Dissertation: Improved characterization techniques for branched polysaccharides
Promotor: prof. K.U. Loos
Faculty: Mathematics and Natural Sciences
Polymers are molecules, which consist of many repeating units (monomers). Starch and glycogen are natural polymers, and they are all around us. We use them on a daily basis but we do not understand them completely. Even though these sugars are simple concerning what they are made of (the repeating unit is glucose), they are hard to characterize. If there is a slight change in structure, polymers’ properties can vary a lot. For instance, a molecule of amylose consists of many glucose units that are connected via α-(1,4) linkages creating a long linear chain, which is insoluble in water. Whereas amylopectin actually represents a long amylose chain with many shorter chains (branches) connected to it with α-(1,6) linkages, and it is soluble in water.
In order to try to understand as much as possible about their structure and the relationship between molecular structure and the physical properties, the first steps are to create such polysaccharides. If you try to synthesize them via traditional organic chemistry, it is very hard and time consuming. Nevertheless if we copy nature and use enzymes as catalysts, the reaction is very easy. Enzymes catalyze specific things, like the formation of α-(1,4) or α-(1,6) linkages for synthetic amylose and amylopectin analogs respectively.
This thesis concentrates on the enzymatic synthesis of these analogs and their meticulous characterization with various techniques. Gathered information are used for unraveling parts of the synthesis mechanism and can be used in future for improved characterization and apprehension of natural polysaccharides.