Structural studies of. cap alpha. -bungarotoxin. 3. Corrections in the primary sequence and X-ray structure and characterization of an isotoxic. -->. -bungarotoxin

Journal Article · Tue Apr 19 04:00:00 EDT 1988 · Biochemistry; (United States)

OSTI ID:7253192

Kosen, P A; Finer-Moore, J; McCarthy, M P; Basus, V J

The most plausible set of chemical shift assignments for ..cap alpha..-bungarotoxin as deduced from the combined use of two-dimensional J-correlated and two-dimensional nuclear Overhauser effect /sup 1/H nuclear magnetic resonance (NMR) spectroscopy was in conflict with the accepted amino acid sequence between residues 8 and 12 and residues 66 and 70. Furthermore, NMR spectra of ..cap alpha..-bungarotoxin, purified by conventional methods, evidenced a second species at the level of approximately 10% total protein. The minor component was separated from ..cap alpha..-bungarotoxin by Mono-S (cationic) chromatography. Sequencing of Mono-S-purified ..cap alpha..-bungarotoxin and one of its tryptic peptides showed that the correct sequence for ..cap alpha..-bungarotoxin in Ser-Pro-Ile at positions 9-11 and Pro-His-Pro at positions 67-69. The electron density map of ..cap alpha..-bungarotoxin was refined with the new sequence data. Improvements in the structure were found primarily for residues 9-11. Sequence analysis of two overlapping tryptic peptides proved that the minor species differed from ..cap alpha..-bungarotoxin by replacement of a valine for an alanine at position 31. This new toxin, ..cap alpha..-bungarotoxin/sup (Val-31)/, binds to the acetylcholine receptor with an affinity that is comparable to that of ..cap alpha..-bungarotoxin.

• Research Organization: Univ. of California, San Francisco (USA)
• OSTI ID: 7253192
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:8; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ACETYLCHOLINE
AMINES
AMINO ACID SEQUENCE
AMMONIUM COMPOUNDS
ANTIGENS
AUTONOMIC NERVOUS SYSTEM AGENTS
BARYONS
BETA DECAY RADIOISOTOPES
CHEMICAL SHIFT
COHERENT SCATTERING
DAYS LIVING RADIOISOTOPES
DIFFRACTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ELEMENTARY PARTICLES
ESTERS
FERMIONS
HADRONS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAGNETIC RESONANCE
MATERIALS
MOLECULAR STRUCTURE
NEUROREGULATORS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OVERHAUSER EFFECT
PARASYMPATHOMIMETICS
PROTONS
PURIFICATION
QUATERNARY COMPOUNDS
RADIOISOTOPES
RADIORECEPTOR ASSAY
RESONANCE
SCATTERING
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
X-RAY DIFFRACTION