t ENOD40B, a plant peptide hormone, was doubly labeled with C-13 and N-15 by recombinant production in Escherichia coli. The peptide was prepared by affinity chromatography followed by protease cleavage and reverse-phase chromatography. To elucidate the mode of action against its receptor, sucrose synthase, we proceeded to assign the backbone and side-chain resonances using a set of double and triple resonance experiments. This result will be used to determine the three-dimensional structure of the peptide at its bound state as well as to observe the chemical shift changes upon binding.

The Strain-Promoted Azide-Alkyne Cycloaddition (SPAAC) is a powerful method for synthesizing triazoles, even under physiological conditions, without a copper catalyst. This technique provides an efficient means for everyone to synthesize complex triazole derivatives rapidly. In order to investigate the configuration of triazole derivatives using bicyclo[6.1.0.]-nonyne (BCN) and chiral azide, it is necessary to employ the 2D NMR. Both 1D and 2D NMR (COSY, HSQC, ¹⁵N HMBC) are used to analyze the complex triazole product containing cyclooctyne, a diastereomeric product. The stereometric difference of the proton bonded to the same carbon is determined through the HSQC assignment. The intriguing splitting pattern of carbon resonances also reveals their diastereomeric configuration and will aid in further research based on physiological knowledge.