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D B Gilbert

Publications and source records attributed to D B Gilbert.

28 records · Page 2Linked to original sources

Distinctive protein profiles obtained from extracts of normal and atherosclerotic human aorta.

Specific areas of fourteen autopsied abdominal aortas were layer-dissected, histologically graded and solubilzed with SDS, dilute saline or SDS-urea and beta-mercaptoethanol. Comparisons were made between intima, media, lesions of progressive severity and an in-vivo thrombus. Apparent molecular weights were calculated from the Coomassie blue stained gels of these extracts extracts and each band's contribution estimated by integrative densitometry. Four minor high moleucular weight bands and six medium to low molecular weight bands were detected in the arterial extracts. Band intensity stain patterns of normal intima are easily distinguished from normal media. Extracts of minor lesions resemble normal media; higher grade lesions demonstrate increased amounts of characteristic initmal bands. The major medial band is also seen on gels of thrombus extracts. Both of the bands most characteristic of atherosclerotic lesions stain for carbohydrate. Isolation and characterization of these (glyco)proteins will provide material for binding studies. Quantitation of characteristic lesion proteins may provide insights into the proliferative phase of this disease.

Adult↗

Thermodynamic equilibria of cholesterol-detergent-water.

Cholesterol monomer is incorporated into alkyl sulfate micelles with a unitary free energy of -10.3 kcal/mol. This experimental free energy is in good agreement with that predicted by our previous determination of the hydrophobicity of the sterol suggesting that the partitioning is primarily hydrophobic with little or no contribution to the free energy from head group interactions in this system. The intrinsic hydrophobicity of cholesterol is shown to be insufficient for effective partitioning of the sterol between micelles (or bilayers) and its own self-associated form. This finding strongly supports a model of phospholipid-cholesterol interaction involving significant free energy contributions from head group effects such as alterations in hydrogen bonds or hydration. Since these head group contributions are not observed in the cholesterol-alkyl sulfate system, one concludes that there is a high degree of specificity of interaction between the sterol OH and polar moieties of other amphiphilic molecules.

Binding Sites↗

Cholesterol in aqueous solution: hydrophobicity and self-association.

Free energies of transfer of cholesterol monomer from water to organic solvents show that the hydrophibicity of this sterol molecule is significantly less than predicted from hydrophobic surface area considerations. It is suggested that this phenomenon may arise from unusual orientation of water molecules at the surface of the solute. From the direct measruemtn of the hydrophobic free energy of transfer and comparison with thermodynamic data on micelle formation reported previously we calcuate specific attractive interactions between cholesterol monomers in the micelle of 2-4 kcal/mol, which suggests the possiblity of self-association (phase separation) in mixed micellar systems such as sterol-lipid complexes.

Binding Sites↗