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This  thesis  is  divided  into  four  parts,  all  centered  around  Constitutional Dynamic  Chemistry  (CDC)  and  Dynamic  Kinetic  Resolution  (DKR)  using biocatalysts for selective transformations, and their applications in screening of bioactive compounds, organic synthesis, and enzyme classification.    In  part  one,  an  introduction  to  CDC  and  DKR  is  presented,  illustrating  the basic  concepts,  practical  considerations  and  potential  applications  of  such dynamic systems, thus providing the background information for the studies in the following chapters.   In part two, Dynamic Systemic Resolution (DSR), a concept based on CDC is exemplified.  With  enzyme-catalyzed  transformations  as  external  selection pressure,  optimal  structures  can  be  selected  and  amplified  from  the  system. This  concept  is  expanded  to  various  types  of  dynamic  systems  containing single, double cascade/parallel, and multiple reversible reactions. In addition, the  substrate  selectivity  and  catalytic  promiscuity  of  target  enzymes  are  also investigated.   In   part   three,   DKR   protocols   using   reversible   reactions   for   substrate racemizations  are  illustrated.  Biocatalysts  are  here  employed  for  asymmetric transformations,  resulting  in  efficient  synthetic  pathways  for  enantioenriched organic compounds.   Part  four  demonstrates  two  unique  applications  of  CDC:  one  resulting  in enzyme  classification  by  use  of  pattern  recognition  methodology;  the  other involving  enzyme  self-inhibition  through  in  situ  transformation  of  stealth inhibitors employing the catalytic activity of the target enzyme. / <p>QC 20130614</p>

Dynamic systems for screening, control and identification of different protein-ligand interactions are presented. Dynamic chemistry is used to produce new compounds/constituents in situ that can interact with a target molecule. Several entities can be introduced at the same time and interact with one another. These molecules make a dynamic combinatorial library (DCL) which is used in dynamic combinatorial chemistry (DCC). DCC is a recently introduced approach to generate dynamically interchanging libraries of compounds. These libraries are made of different building blocks that reversibly interact with one another and spontaneously assemble to encompass all possible combinations. If a target molecule, for instance a receptor is added to the system and one or more molecules show affinity to the target species, these compounds will, according to Le Châtelier´s principle, be amplified on the expense of the other non-bonding constituents. To further advance the technique, especially when biological systems are targeted, new reaction types and new screening methods are necessary. This thesis describes the development of different reversible reactions, thiol/disulfide interchange, transthiolesterification and the nitroaldol (Henry) reaction as means of generating reversible covalent bond reactions. Two different types of target proteins are used, enzymes belonging to the hydrolase family and the plant lectin Concanavalin A. Dynamic combinatorial resolution (DCR) is presented. This new concept relies on the consecutive kinetic resolution of dynamic combinatorial libraries, leading to complete amplification and control of dynamically interchangeable processes. By applying a kinetically controlled step to a thermodynamically controlled system, complete transformation and amplification can be obtained. The concept has been demonstrated by developing transthiolesterification and nitroaldol exchange reactions to generate diversity, forming libraries under thermodynamic control, and used in one-pot processes with kinetically controlled enzyme-mediated resolution. The results demonstrate that the reaction types are useful for the generation of dynamic libraries, and that the dynamic combinatorial resolution concept is highly valuable for efficient substrate identification, asymmetric synthesis, and library screening. The thesis also describes three other dynamic chemistry protocols. The first one describes dynamic kinetic resolution (DKR) of nitroaldol adducts by combined lipase catalysis. The second one describes finding lectin inhibitors from a glycodisulfide library and the third one describes finding an inhibitor of acetylcholinesterase using a tandem driven dynamic self-inhibition approach. / <p>QC 20100818</p>

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