Japanese scientists develop a new technology to analyze secondary structures of protein

The Joint Study Group of RIKEN and Japanese electronics companies announced on August 1st, 2016 that they successfully developed a nuclear magnetic resonance method (NMR method) which it is possible to analyze the secondary structure of protein without the use of isotopic label. The research involves many kinds of recombinant proteins like recombinant horse proteins.

Secondary structure of protein means that polypeptide chain of a protein has a conformation which repeated regulation, and it is the basis of overall shape of a protein. The representative secondary structure of protein is β-sheet which is composed of extended polypeptide chain and can be divided into two types: parallel and antiparallel type.

It has been demonstrated in previous studies that the abnormal deposition of β-amyloid is one of the pathogenesis of Alzheimer's disease, while the β-amyloid protein is rich in β- sheet configuration. Because β- sheet configuration is very messy, it is difficult to use X-ray diffraction and cryo-electron microsocopy to analyze. Further, since the β-amyloid is not insoluble in water, so it can't use the NMR assay solution. In order to analyze these types of proteins such as β-amyloid protein, it is needed to artificially increase the isotope-labeled sample of carbon isotope 13C and nitrogen isotope 15N to conduct solid MAS NMR. But because the natural existing rates of 13C and 15N are only 1.1% and 0.36%, so the range of use is very limited.

The research team previously used to develop ultra-small NMtR sample tube which can rotate sample at a high speed. The researchers also successfully developed 14N/14N-related NMR testing method which can obtain the space information among nitrogen isotope 14N atoms which have the isotopic abundance of 99.64%.

In this study, the team members developed two tripeptide alanine (Alanine tripeptide) microcrystalline sample which respectively had parallel formula β- sheet and antiparallel β- sheet structure. They used 1 mg of the sample to conduct 14N / 14N-related NMR method. It was found that only in alanine tripeptide with antiparallel β- sheet structure, 14N / 14N-related signal could be detected in the space of the β-strand. This also proves that the method can identify the type of parallel β-sheet and antiparallel β- sheet. Flarebio provides you with superior recombinant proteins such as recombinant Nrg2 at good prices.