NMR chemical shift dependence on medium ionic strength for poly(. cap alpha. )-L-glutamic acid in D/sub 2/O solutions

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Anal. Lett.; (United States)

DOI:https://doi.org/10.1080/00032717708067836· OSTI ID:5345213

Gearhart, H L; Sawyer, II, W P

Four molecular weight samples (DP 37, DP 90, DP 565 and DP 650) of poly(..cap alpha..)-L-glutamic acid were studied in aqueous salt solutions. NaCl concentrations were varied between 0.05 M and 1.5 M for the above polymer solutions. NMR spectra, including proton (60 and 100 MHz) and /sup 13/C were determined. Chemical shifts (relative to tetramethylsilane) were measured as a function of pH. In the lower molecular weight polypeptide samples studied the ..cap alpha..-CH resonance bands over the pH range favoring randon coil conformations were displaced downfield with increasing salt concentrations. At high background salt concentrations, the molecular weight dependence of chemical shift was observed to disappear.

• Research Organization: Oklahoma State Univ., Stillwater
• OSTI ID: 5345213
• Journal Information: Anal. Lett.; (United States), Journal Name: Anal. Lett.; (United States) Vol. 10:11; ISSN ANALB
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
CHEMICAL SHIFT
DEUTERIUM
HEAVY WATER
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PEPTIDES
POLYPEPTIDES
PROTEINS
RESONANCE
STABLE ISOTOPES
WATER