Structural characterization of compact peptides from staphylococcal nuclease by circular dichroism and nuclear magnetic resonance spectroscopy
Year: 1996
Type: article
Abstract: Structural domains arc regions of proteins that fold spontaneously, even when removed from the intact protein.Several studies have linked the presence o f structural domains with physically compact regions in proteins.An algorithm to locate domains in proteins based on compactness has been developed and used to analyze several proteins (M.H. Zchfus, Prot, Eng.7: 335*340, 1994).When applied to staphylococcal nuclease, several compact units were located.One of the most compact units corresponded to a small 13 residue peptide comprising residues 129-141 and one o f the larger units corresponded to residues 99-140.If these peptides arc truly structural domains, they should retain native-like structure when cleaved from the intact protein.To see if this was true, peptides corresponding to these two peptides were obtained by chemical synthesis or recombinant techniques coupled with chemical cleavage.In aqueous solution, the small 13 residue peptide exhibited CD spectra characteristic o f a nascent helix.This nascent helical structure was stabilized by the addition o f 2,2,2-trifluorocthanol (TFE), Under those conditions, the chemical shift indices (CSI), temperature coefficients, and NOE constraints were all consistent with the peptide's structure being a helix-tum.This structure is very similar to that found in the intact protein.CD spectra o f staphylococcal nuclease in aqueous solution at pH 4.0, pH 7.0, and pH 10.0....................
Author: Mark W. Maciejewski
Institution: The Ohio State University
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2800990176