Understanding of the effects of the backbone cyclization on the structure and dynamics of a protein is essential for using protein topology engineering to alter protein stability and function. Here we have determined, for the first time, the structure and dynamics of the linear and various circular constructs of the N-SH3 domain from protein c-Crk. These constructs differ in the length and amin...

The selectivity of our previously described gold-catalyzed tandem reaction, 1,2-indole migration followed by aura-iso-Nazarov cyclization, of 3-propargylindoles bearing (hetero)aromatic substituents at both the propargylic and terminal positions, was reversed by the proper choice of the catalyst and the reaction conditions. Thus, 3-(inden-2-yl)indoles, derived from an aura-Nazarov cyclization (...

The cyclization-carbonylation-cyclization coupling reaction (CCC-coupling reaction) of propargyl ureas catalyzed by Pd(II)(box) complexes afforded symmetrical ketones bearing two 2-amino-2-oxazoline groups in good to moderate yields.

Cavities formed using cyclic tetrapeptides (CTPs) or heat-induced conformers act as templates for cyclization; the cavities bind to linear tetrapeptides and enforce turn conformations to enhance cyclization to constrained CTPs.

Enzymes catalyze reactions with exceptional selectivity and rate acceleration but are often limited by instability. Towards a generic route to thermo-resilience, we established the SpyRing approach, cyclizing enzymes by sandwiching between SpyTag and SpyCatcher (peptide and protein partners which lock together via a spontaneous isopeptide bond). Here we first investigated the basis for this res...

Stabilization of an enzyme while maintaining its activity has been a major challenge in protein chemistry. Although it is difficult to simultaneously improve stability and activity of a protein by amino acid substitutions due to the activity-stability trade-off, backbone cyclization by connecting the N and C termini with a linker is promising as a general method of stabilizing a protein without...

The product template (PT) domains, specifically in fungal non-reducing polyketide synthases (NR-PKSs), mediate the regioselective cyclization of polyketides dominating the final structures. However, up to date, the systematic knowledge about PT domains has been insufficient. In present study, the relationships between sequences, structures and functions of the PT domains were analyzed with 661 ...

[reaction: see text]Cyclization of the optically active ketone N,N-dialkyl aminals A affords the diastereomer B as the major product with diastereoselectivities ranging from nearly 1:1 to essentially 100:0 depending on the cyclization studied.

The 5-endo-trig-type cyclization has been performed using a Pd-bis(isoxazoline) catalyst. The present cyclization of β,γ-unsaturated carbonyl compounds gave γ-butenolides and 3-pyrrolin-2-ones in good to excellent yields.