Alan E. Rowan

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The precursor formamide 1 was employed instead of the monomer 2 because isocyanides are relatively unstable in air at room temperature. [19] a) [20] Molecular modeling shows that (in common with the phenyl benzo-ate compounds previously described [17]) an angle exists between the planar phenoxy and TTF ring systems. [21] The oxidation of the polymer was(More)
Nature has evolved complex enzyme architectures that facilitate the synthesis and manipulation of the biopolymers DNA and RNA, including enzymes capable of attaching to the biopolymer substrate and performing several rounds of catalysis before dissociating. Many of these 'processive' enzymes have a toroidal shape and completely enclose the biopolymer while(More)
Mechanical responsiveness is essential to all biological systems down to the level of tissues and cells. The intra- and extracellular mechanics of such systems are governed by a series of proteins, such as microtubules, actin, intermediate filaments and collagen. As a general design motif, these proteins self-assemble into helical structures and(More)
Using a single-molecule fluorescence approach, the time series of catalytic events of an enzymatic reaction can be monitored, yielding a sequence of fluorescent "on"- and "off"-states. An accurate on/off-assignment is complicated by the intrinsic and extrinsic noise in every single-molecule fluorescence experiment. Using simulated data, the performance of(More)
The use of bottom-up approaches to construct patterned surfaces for technological applications is appealing, but to date is applicable to only relatively small areas (approximately 10 square micrometers). We constructed highly periodic patterns at macroscopic length scales, in the range of square millimeters, by combining self-assembly of disk-like(More)
Exploiting tapping mode-scanning force microscopy (TM-SFM), we characterized single polymeric chains of poly(isocyanodipeptides) (PICs) equilibrated in quasi two-dimensions on the basal plane of mica surfaces. While the average contour length 〈L〉 of an acid-catalyzed PIC bearing L-alanine-D-alanine methyl ester groups was as high as 5.3 µm, the(More)
Copper-free click chemistry between cyclooctynes and azide is a mild, fast and selective technology for conjugation of oligonucleotides. However, technology for site-specific introduction of the requisite probes by automated protocols is scarce, while the reported cyclooctynes are large and hydrophobic. In this work, it is demonstrated that the introduction(More)
The stiffness of hydrogels is crucial for their application. Nature's hydrogels become stiffer as they are strained. This stiffness is not constant but increases when the gel is strained. This stiffening is used, for instance, by cells that actively strain their environment to modulate their function. When optimized, such strain-stiffening materials become(More)
Polymerization of isocyanopeptides results in the formation of high molecular mass polymers that fold in a proteinlike fashion to give helical strands in which the peptide chains are arranged in beta-sheets. The beta-helical polymers retain their structure in water and unfold in a cooperative process at elevated temperatures. The peptide architecture in(More)
A state sequence was first produced by performing a random walk in the kinetic scheme (as a Markov model, see Fig. 1) with the corresponding state-to-state transition probabilities given by the rate constants listed in table S1. The chosen time step (10 s) of the random walk was much smaller than the time scales specified by all the rates. The random state(More)