When the three-dimensional structures of many different protein molecules are compared, it becomes clear that, although the overall conformation of each protein is unique, two regular folding patterns are often found in parts of them. Both patterns were discovered about 50 years ago from studies of hair and silk. The first folding pattern to be discovered, called the α helix, was found in the protein α-keratin, which is abundant in skin and its derivatives—such as hair, nails, and horns (Eisenberg et al., 2003). Within a year of the discovery of the α helix, a second folded structure, called a β sheet, was found in the protein fibroin, the major constituent of silk (Lefèvre et al., 2007). These two patterns are particularly common because they result from hydrogen-bonding between the N–H and C=O groups in the polypeptide backbone, without involving the side chains of the amino acids. Thus, they can be formed by many different amino acid sequences. In each case, the protein chain adopts a regular, repeating conformation. (Alberts et al., 2002)
Reference
Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., and Walter, P. (2002) Molecular biology of the cell (4th ed.). Garland Science. https://www.ncbi.nlm.nih.gov/books/NBK26830/
Sample 1:
α helix protein structure was discovered first followed by β sheet (Alberts et al., 2002; Eisenberg, 2003; Lefèvre et al., 2007). The former was found in keratin protein while the latter was found in fibroin protein. These structures can be commonly found in different proteins as they are involved in hydrogen bonds between amino acids. (Alberts et al. 2002).
Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., and Walter, P. (2002) Molecular biology of the cell (4th ed.). Garland Science. https://www.ncbi.nlm.nih.gov/books/NBK26830/
Eisenberg, D. (2003). The discovery of the alpha-helix and beta-sheet, the principal structural features of proteins. Proceedings of the National Academy of Sciences of the United States of America, 100(20), 11207–11210. https://doi.org/10.1073/pnas.2034522100
Lefèvre, T., Rousseau, M. E., & Pézolet, M. (2007). Protein secondary structure and orientation in silk as revealed by Raman spectromicroscopy. Biophysical Journal, 92(8), 2885–2895. https://doi.org/10.1529/biophysj.106.100339
Q1: Does sample 1 use the in-text citations appropriately without plagiarism?
- Yes
- No
