Folate binding protein may participate in folate homeostasis by regulating monoglutamyl folate transport across relevant cell membranes. We compared the activity, immunoreactivity, and transcripts of folate binding protein in pig liver, kidney, and jejunal mucosa and their relevant cell membranes. Binding of [3H]folic acid was sixfold greater to pig liver plasma membranes than to kidney brush-b...

The actin-activated Mg(2+)-ATPase activities of Acanthamoeba myosins I are known to be maximally expressed only when a single threonine (myosin IA) or serine (myosins IB and IC) is phosphorylated by myosin I heavy chain kinase. The purified kinase is highly activated by autophosphorylation and the rate of autophosphorylation is greatly enhanced by the presence of acidic phospholipids. In this p...

The in vitro effect of polybrominated biphenyls (FireMaster BP-6) on adenylate cyclase [ATP pyrophosphate lyase (cyclizing), EC 4.6.1.1] activity in plasma membranes of rat lung alveoli was determined. Two fractions of plasma membranes, PM-I (approximate d = 1.13 g/cm3) and PM-II (approximate d = 1.16 g/cm3) were isolated under hypotonic homogenization and fractionation conditions (1mM NaHCO3, ...

3T3 plasma membranes were added to subconfluent cultures of SV3T3 cells in the presence of fusogens. If this protocol results in the introduction into the SV3T3 cell membrane of 3T3 plasma membrane components responsible for density-dependent inhibition of growth, then the SV3T3 cell cultures would be expected to show decreased rates of DNA synthesis as they approach confluence. Results of thes...

Escherichia coli O111a is a thermosensitive strain which, when grown at 40 C, accumulates large quantities of intracellular membranes. The ultrastructure of these membranes in cells which have been chemically fixed, embedded, and examined as thin sections has been compared with that of membranes in cells negatively stained or freeze-fractured. Results indicate that the extra membranes are prese...

Anisotropy of anionic sites on plasma membranes has been implicated in contact phenomena at cell surfaces (16, 17). Recent evidence indicates that charge anisotropy may be important among intracellular membranes also, since distribution of anionic sites has been related to structural organization of mitochondrial membranes (8). The use of cationic ferritin has been introduced by Danon et al. (2...

Plasma membranes derived from rat thyroid tumor (1-8R) which is unresponsive to thyrotropin but is responsive to dibutyryl adenosine 3':5'-cyclic monophosphate bind less than 20% of the [125I] thyrotropin which can be bound to plasma membranes from normal rat thyroids under conditions which optimize tumor membrane binding relative to normal thyroid membranes. In addition, the binding is differe...

Antibodies that reacted with plasma membranes of human eye muscle but showed no binding to plasma membranes of human skeletal muscle were identified in serum of patients with Graves' ophthalmopathy. Rabbit antithyroglobulin serum at a dilution of 1 X 10(-3) to 20 X 10(-3) had no effect on the binding of these antibodies to eye muscle membrane antigens. There was no correlation between antihuman...

Improvement of methods complex treatment periodontium diseases continues to be an urgent problem dentistry and requires interdisciplinary approach. The severity the course periodontitis destructive phenomena dictates need use osteoplastic agents restore damaged tissues. It has been proven that efficiency membrane technology is significantly increased when membranes substitute materials are used...

Although investigation into the structure of eukaryotic cell membranes has been an intense focus of cell biology for the past two decades, definitive insights have been limited by the lack of coherent methods for the isolation of specific organelle membranes and the identification of membrane subdomains. Here we describe a method for the isolation of mammalian cell plasma membranes as Giant Pla...