title: Amino acid analysis of spider dragline silk using ¹H NMR.
abstract: The amino acid composition of Nephila clavipes dragline silk fiber was determined by conducting ¹H nuclear magnetic resonance (NMR) spectroscopy experiments on acid-hydrolyzed material. N. clavipes dragline silk was found to consist of 43.0±0.6% Gly, 29.3±0.2% Ala, 9.1±0.1% Glx, 4.0±0.1% Leu, 3.3±0.1% Tyr, 3.4±0.2% Ser, 2.7±0.1% Pro, 2.1±0.1% Arg, 1.07±0.05% Asx, 0.96±0.05% Val, 0.48±0.03% Thr, 0.35±0.03% Phe, and 0.28±0.03% Ile. Compared with standard chromatography-based amino acid analysis (AAA), the chemical resolution of NMR allows for an amino acid solution to be characterized without separation and is shown to provide considerably higher precision. This allows for more accurate statistics on the variability of amino acids in spider dragline silk. In general, this ¹H NMR AAA technique is applicable to a large range of proteins and peptides for precise composition characterization, especially when the precise content of a minor component is critical and relatively large amounts of sample are available (microgram to milligram quantities).
authors.affiliation: Department of Chemistry and Biochemistry, Magnetic Resonance Research Center, Arizona State University, Tempe, AZ 85287-1604, USA.
authors.forename: Xiangyan
authors.initials: X
authors.lastname: Shi
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Holland
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Yarger
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000737:chemistry*; D000818:Animals; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D047011:Silk / Q000737:chemistry*; D013112:Spiders
chemical_list: D000596:Amino Acids; D047011:Silk
keywords: (1)H NMR; Amino acid analysis; Nephila clavipes dragline silk; Spider silk