671224-34-3Relevant academic research and scientific papers
An efficient one-pot four-segment condensation method for protein chemical synthesis
Tang, Shan,Si, Yan-Yan,Wang, Zhi-Peng,Cheng, Jing-Yuan,Liu, Lei,Mei, Kun-Rong,Chen, Xin,Zheng, Ji-Shen
, p. 5713 - 5717 (2015)
Successive peptide ligation using a one-pot method can improve the efficiency of protein chemical synthesis. Although one-pot three-segment ligation has enjoyed widespread application, a robust method for one-pot four-segment ligation had to date remained undeveloped. Herein we report a new one-pot multisegment peptide ligation method that can be used to condense up to four segments with operational simplicity and high efficiency. Its practicality is demonstrated by the one-pot four-segment synthesis of a plant protein, crambin, and a human chemokine, hCCL21. Pick up a peptide: Tfacm-protected cysteine is readily activated by pH adjustment, enabling the development of a highly efficient one-pot four-segment ligation method. Two proteins, crambin and the chemokine hCCL21, are prepared using this rapid and high-yielding synthetic route.
Homogeneous human complex-type oligosaccharides in correctly folded intact glycoproteins: Evaluation of oligosaccharide influence on protein folding, stability, and conformational properties
Kajihara, Yasuhiro,Tanabe, Yasutaka,Sasaoka, Shun,Okamoto, Ryo
supporting information; scheme or table, p. 5944 - 5953 (2012/07/14)
The N-glycosylation of proteins is generated at the consensus sequence NXS/T (where X is any amino acid except proline) by the biosynthetic process, and occurs in the endoplasmic reticulum and Golgi apparatus. In order to investigate the influence of human complex-type oligosaccharides on counterpart protein conformation, crambin and ovomucoide, which consist of 46 and 56 amino acid residues, respectively, were selected for synthesis of model glycoproteins. These small glycoproteins were intentionally designed to be glycosylated at the α-helix (crambin: 8 position), β-sheet (crambin: 2 position) and loop position between the antiparallel β-sheets (ovomucoide: 28 position), and were synthesized by using a peptide-segment coupling strategy. After preparation of these glycosylated polypeptide chains, protein folding experiments were performed under redox conditions by using cysteine-cystine. Although the small glycoproteins bearing intentional glycosylation at the α-helix and β-sheet exhibited a suitable folding process, glycosylation at the loop position between the antiparallel β-strands caused multiple products. The conformational differences in the isolated homogeneous glycoproteins compared with non-glycosylated counterparts were evaluated by circular dichroism (CD) and NMR spectroscopy. These analyses suggested that this intentional N-glycosylation did not result in large conformational changes in the purified protein structures, including the case of glycosylation at the loop position between the antiparallel β-strands. In addition to these experiments, the conformational properties of three glycoproteins were evaluated by CD spectroscopy under different temperatures. The oligosaccharides on the protein surface fluctuated considerably; this was dependent on the increase in the solution temperature and was thought to disrupt the protein tertiary structure. Based on the measurement of the CD spectra, however, the glycoproteins bearing three disulfide bonds did not exhibit any change in their protein tertiary structure. These results suggest that the oligosaccharide conformational fluctuations were not disruptive to protein tertiary structure, and the tertiary structure of glycoproteins might be stabilized by the disulfide bond network. Copyright
