Molecular basis for the temperature-dependent insolubility of cryoglobulins. XII. Anomalous mobility of monoclonal cryoimmunoglobulin heavy chains accompanying polyacrylamide gel electrophoresis in sodium dodecyl sulfate.

When subjected to polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS), the fully reduced and alkylated heavy chains isolated from three monoclonal IgG1 cryoimmunoglobulins exhibited various degrees of retardation in mobility when compared to noncryoglobulin references. The anomalous electrophoretic mobility was not correlated with the thermal magnitude of cryoprecipitation of the individual proteins. High sensitivity analytical gel filtration in 5 M guanidine-HCl failed to distinguish heavy chains of the cryoimmunoglobulins from noncryoglobulin references, suggesting that the proteins possess equivalent molecular weights.

Light-activated calcium release from sonicated bovine retinal rod outer segment disks.

Calcium trapped within sonicated and resealed bovine rod outer segment disks is released upon light exposure with a stoichiometry of 0.75 +/- 0.05 calcium for each rhodopsin bleached.

Analysis of lipophilic carcinogen-membrane interactions using a model human erythrocyte membrane system.

Human erythrocytes have been used as a model for evaluating the chemical carcinogen-plasma membrane interaction. The carcinogenic aromatic amines 2-acetylaminofluorene, dimethylaminoazobenzene, and 3'-methyldimethylaminoazobene stabilize erythrocytes against lysis in hypotonic solution. In general, the stabilization potential of these compounds reflects their oil:water partition coefficients and may be related to both their extracellular distribution and ultimate capacity for penetration of target cells.

Analysis of polypeptide disposition in human erythrocyte membranes employing membrane inversion.

High resolution segregation of erythrocyte membrane polypeptides achieved by isoelectric focusing in 8 M urea was employed in conjunction with surface-restricted radioiodination to analyze the disposition of polypeptides within the human erythrocyte membrane. Several membrane polypeptides showed significant uptake of radioiodine, with the principal labeled component migrating between pH values of 3.0 and 3.