The critical micelle condition revisited.

Several simple alternatives have been examined as a possible basis for micellar size distributions which are internally consistent with the experimentally required concept of a threshold concentration, the critical micelle condition. Among these are the two-state system, monomer in equilibrium with a single high polymer, indefinite self-association, and continuous self-association with an arbitrary upper limit beyond which all further association is absolutely prohibited. Of these, only the last is a possible choice, although lacking experimental support.

Pressure-jump kinetics of bovine beta-casein micellization.

Two samples of highly purified bovine beta-casein supplied to us by Dr. T.A.

A micelle model for the sedimentation behavior of bovine beta-casein.

The monomer-single polymer model of G.A. Gilbert (Disc.

Perturbation of ribosome subunit interaction by glutaraldehyde fixation.

Ultracentrifugal analysis of ribosomal purity is complicated by the rapid reequilibration of ribosomes with their subunits, and this is further enhanced by the effects of hydrostatic pressure. Fixation of the ribosome system prior to ultracentrifugal analysis supposedly freezes the reequilibration, and thus tends to obviate these difficulties. However, no redistribution of the ribosome-subunit population must be allowed to occur during fixation.

Models for the analytical ultracentrifuge behavior of Helix pomatia alpha-hemocyanin. I. Experimental testing of previous models.

The 'microheterogeneity model' (R.J. Siezen and R.

Relaxation kinetics of E. coli ribosomes: evidence for the reaction of 30S . IF3 complex with 50S ribosomal subunits.

Addition of initiation factor IF3 to solutions of E. coli ribosomes dramatically alters their behavior in pressure-jump relaxation kinetic experiments in which 90 degrees light-scattering is used to monitor the macromolecular reaction. The effect of IF3 on relaxation processes attributed to "tight" couples is strongly dependent on the Mg2+ concentration.

Volume of reaction by the Archibald ultracentrifuge method (lobster hemocyanin).

Samples of lobster hemocyanin (Homarus americanus) under conditions of reversible reaction between whole (25 S) and half (17 S) molecules have been subjected to accurately known nitrogen pressures in analytical ultracentrifuge cells. A modified pressurization chamber of the type developed by Schumaker and colleagues has been constructed for this purpose. The molecular weight was then determined at the top (liquid-gas) meniscus, by means of the Archibald method.

Mechanism of the hexamer-dodecamer reaction of lobster hemocyanin.

The overall forward and reverse rate constants for the hexamer-dodecamer reaction of lobster hemocyanin have been determined in 0.1 ionic strength glycine buffers at pH 9.6, at free calcium ion levels from 0.

Relaxation kinetics of E coli ribosomes: evidence for the reaction of 30S . IF3 complex with 50S ribosomal subunits.

Addition of initiation factor IF3 to solutions of E.coli ribosomes dramatically alters their behavior in pressure-jump relaxation kinetic experiments in which 90 degrees light-scattering is used to monitor the macromolecular reaction. The effect of IF3 on relaxation processes attributed to "tight" couples is strongly dependent on the Mg2+ concentration.

Z-average sedimentation coefficient in reversibly self-aggregating systems.

A theoretical treatment of the determination of the Z-average sedimentation coefficient in reversibly self-aggregating systems is presented. These equations are useful for determination of formation constants of polymers.