In the April 30 issue of "American Chemical Society" (JACS, 2008, 130, 5798), on which reported Dr. Yang Jun used Solid-state NMR to study protein interface in the United States University of Delaware.

　　A number of biological macromolecules, such as membrane proteins, protein complexes, protein fibers, etc., which play an extremely important role in life progress, but because of difficulties in obtaining single crystals of these biological molecules and their low solubility in solution, using X - ray and liquid NMR is difficult to get their structure. A typical example is the membrane protein. In the human gene encoding the protein, about 30% is membrane protein, which have closed relation with a number of important life activities such as energy conversion, information identification and delivery, material delivery and distribution. But so far, only 157 species (a total of about 30,000 kinds of) have been known their three-dimensional structure. For these "difficult" biological macromolecules, Solids-NMR is considered the most promising means of study. Since 2002 German scientists used the magic angle spinning NMR to determine three-dimensional structure of proteins for the first time, it developed rapid in recent years in this area. With the use of high magnetic field NMR instruments, developing of magic angle spinning NMR probe technology, solid protein sample preparation technology matures and a number of two to four dimensional NMR pulse sequence to use in magic angle spinning NMR, it has been able to carry out 25-30 KD protein NMR signals assigned and the corresponding study of the structure and dynamics.

　　In this study, Yang and the University of Delaware colleagues Tatyana Polenova designed a new set of pulse sequence, they used this group of pulse sequence studied the within and between molecules interface of thioredoxin with different isotope-labeled. First, they used theoretical simulation and NMR experiments confirmed the REDOR solid NMR techniques can be used to eliminate 15N signals in 13C, 15N enrichment main chain, a protein sample at the same time attribution of NMR signals and proteins Interface Research. With the remote interaction sensitive 1H/13C REDOR and PAIN-CP technology, they designed a two pulse sequence, observed space similar residues at interface of protein using different nuclear spin pair, In addition, they also designed a two-pulse sequences for 15N signals assigned which on the other main chain of protein. This group of solid NMR pulse sequences and the corresponding isotope labeling will be used available in a larger protein complex on the study of the interface.