Quantum mechanics

Magnetic field

Engineering

Chemical physics

Biology

Peptide

Nuclear magnetic resonance spectroscopy

Folding (DSP implementation)

Biochemistry

Protein folding

Stereochemistry

Physics

Astronomy

Molecular dynamics

Computational chemistry

Melittin

Kinetics

Crystallography

Chemistry

Antiparallel (mathematics)

Millisecond

Biophysics

Electrical engineering

Proceedings of the National Academy of Sciences

Significance Many biological processes involve major changes in the structures and assembly states of proteins and other biopolymers. This paper describes an approach to characterizing such processes with millisecond time resolution, based on rapid mixing to prepare an initial structural state, rapid freezing to trap intermediate states, and low-temperature solid-state NMR (enhanced by dynamic nuclear polarization) to probe the structure at successive time points. Results of experiments on melittin, a peptide from bee venom, show that melittin adopts a helical conformation and forms antiparallel dimers on the same timescale (6 to 9 ms). Full structural order within melittin tetramers develops more slowly (roughly 60 ms).

Application of millisecond time-resolved solid state NMR to the kinetics and mechanism of melittin self-assembly