Processive Catalysis

Abstract

Nature's enzymes are an ongoing source of inspiration for scientists. The complex processes behind their selectivity and efficiency is slowly being unraveled, and these findings have spawned many biomimetic catalysts. However, nearly all focus on the conversion of small molecular substrates. Nature itself is replete with inventive catalytic systems which modify, replicate, or decompose entire polymers, often in a processive fashion. Such processivity can, for example, enhance the rate of catalysis by clamping to the polymer substrate, which imparts a large effective molarity. Reviewed herein are the various strategies for processivity in nature's arsenal and their properties. An overview of what has been achieved by chemists aiming to mimic one of nature's greatest tricks is also included.

Glycoluril‐Derived Molecular Clips are Potent and Selective Receptors for Cationic Dyes in Water

“…[1] Nolte’s group pioneered the development of glycoluril molecular clips that feature one glycoluril unit and two covalently attached aromatic sidewalls, studied their fundamental host-guest chemistry in organic solvent (CDCl 3 ) and used them to construct functional architectures. [2] Attachment of solubilizing groups renders these glycoluril molecular clips water soluble which promotes their self-association rather than enabling their recognition properties toward complementary guests. [3] More recently, the supramolecular chemistry of the cucurbit[n]uril family (CB[n], Figure 1) has unfolded rapidly since the disclosure of CB[n] homologues by Kim and Day.…”

“…Of course, a variety of molecular clips and molecular tweezer architectures have been studied over the years [21] most notably by the groups of Nolte, [2] Zimmerman, [22,23] and Klaerner. [24,25] For example, Zimmerman studied molecular tweezers that feature acridine walls held apart by a dibenzoacridine spacer and demonstrated their ability to recognize electron poor aromatic guests including nucleotides in organic solvent.…”

Sensitive Structural Control of Macrocycle Threading by a Fluorescent Squaraine Dye Flanked by Polymer Chains

“…1 Successful rational design of these dynamic systems requires a precise understanding of the structural factors that control the underlying kinetics and thermodynamics. 2 We have previously reported that the macrocyclic tetralactam hosts in Scheme 1 can encapsulate highly fluorescent squaraine dyes to give structurally well-defined pseudorotaxane complexes that are well suited for fluorescence imaging of biological samples.…”

Wholly Synthetic Molecular Machines

“…[138] Nolte [139][140][141][142] has designed ar otaxanet hat mimics the action of these processive enzymes to catalyze many reactions, one after another in ar ow (Figure 13). The synthesis of double-helical DNA, as part of the process of replication, requires that the enzyme DNA polymerase attaches itself to as ingle DNA polymer chain prior to identifying the complimentary nucleotide andc atalyzing the formation of ap hosphate ester bond before movingt o the next nucleotide.…”