Three newcyclic peptides, segetalins B, C and D, were isolated fromVaccariasegetalis (seeds) and their structures were elucidated by 2D NMR and chemical degradations. Conformational analysis of segetalin B, having an estrogen-like effect, was made by using high field NMR and computational methods. Segetalin B was suggested to possess a solution conformation similar to that of segetalin A in the
Characterization of the Fast and Promiscuous Macrocyclase from Plant PCY1 Enables the Use of Simple Substrates
作者:Hannes Ludewig、Clarissa M. Czekster、Emilia Oueis、Elizabeth S. Munday、Mohammed Arshad、Silvia A. Synowsky、Andrew F. Bent、James H. Naismith
DOI:10.1021/acschembio.8b00050
日期:2018.3.16
natively displays substrate promiscuity. PCY1 is a promising candidate for in vitro utilization, but its substrates require an 11 to 16 residue C-terminal recognition tail. We have characterized PCY1 both kinetically and structurally with multiple substrate complexes revealing the molecular basis of recognition and catalysis. Using these insights, we have identified a three residue C-terminal extension