This work examines protein adsorption on surfaces in an attempt to provide a fundamental understanding of the molecular-level mechanism for protein interactions with biomaterials. Carboxylic acid, amine, and hydroxyl terminated self-assembled monolayers (SAMs) are used to model negatively, positively, and hydrophilic/neutrally charged surfaces, respectively. The adsorption of fibrinogen and lys...

The capacitance of skeletal muscle fibers was measured by recording with one microelectrode the voltage produced by a rectangular pulse of current applied with another microelectrode. The ionic strength of the bathing solution was varied by isosmotic replacement of NaCl with sucrose, the [K] [Cl] product being held constant. The capacitance decreased with decreasing ionic strength, reaching a v...

The effect of ionic activity on the quenching of the quinine dication fluorescence by chloride and bromide ions is examined in solutions of sufficiently low ionic strength to enable ionic activities to be taken into account by means of the Debye-Hückel equation. An equation for the dependence of the Stern-Volmer constant on the ionic strength is derived in a novel way and an iterative, linear l...

We present in this article an original approach to compute the electrophoretic mobility of rigid nucleo-protein complexes like nucleosomes. This model allows us to address theoretically the influence of complex position along DNA, as well as wrapped length of DNA on the electrophoretic mobility of the complex. The predictions of the model are in qualitative agreement with experimental results o...

The thermal denaturation of the native DNA in solvents of varying salt concentrations was studied by viscometric and spectrophotometric methods. It was observed that within the molarity range of 0.02 M to 0.3 M, the melting temperatures obtained by the two independent methods agreed well, but that at lower ionic strength the agreement was not satisfactory. Both the visco­ metric and the spectro...

A low-ionic strength-Polybrene (LISP) AutoAnalyzer haemagglutination channel (Lalezari, 1968; Perrault and Hogman, 1971) fails to detect a proportion of antibodies, particularly anti-KI, anti-Lewis, and anti-P1, which can be demonstrated by manual techniques (Moore and Perrrault, 1977). Moore et al. (1977) found that when dialysis was used instead of dilution to achieve a low ionic-strength rea...

alpha-Isopropylmalate isomerase, the second enzyme specific for leucine biosynthesis, can be purified from extracts of yeast utilizing a chromatographic procedure that allows separation of proteins in the presence of high concentrations of (NH4)2SO4. The purification procedure utilizes the stabilizing effect of glycerol and (NH4)2SO4 on the isomerase and their opposing effects on protein retent...

Sodium cholate aggregates are adaptable host systems. The effect of changing the ionic strength with the addition of NaCl on the properties for guest binding to sodium cholate aggregates was investigated by using pyrene, perylene and 1-ethylnaphthalene as guests. Fluorescence, anisotropy and laser flash photolysis studies provided information on the protection efficiency of the aggregate bound ...

Interprotein electron transfer plays an important role in biological energy conversion. In this work, the electron transfer reaction between cytochrome c(2) (cyt) and the reaction center (RC) was studied to determine the mechanisms coupling association and electron transfer. Previous studies have shown that mutation of hydrophobic residues in the reaction interface, particularly Tyr L162, chang...

The effect of ionic strength on the proteolysis by trypsin of the major membrane-penetrating protein (polypeptide 3) in the erythrocyte membrane was studied. Both the intracellular and extracellular regions of the protein are susceptible to trypsin proteolysis under hypo-osmotic conditions, whereas under iso-osmotic conditions the extracellular region of the protein is resistant to trypsin, and...