Blood groups and their function.

M E Reid; V Yahalom

doi:10.1053/beha.2000.0096

Home/Archive/PubMed

PubMed · 11102273

Blood groups and their function.

M E Reid·V Yahalom

View original source ↗Export metadata ↓

Abstract

The function(s) assigned to red blood cell membrane components is based on an observed effect in the red cells that lack the component, comparison of the protein sequence (predicted from the nucleotide sequence of the gene) to proteins of known function, and extrapolation of function of the component in other cells. The functions are varied and include membrane structure, transport, receptor, adhesion, enzyme activity, complement components, complement regulation and glycocalyx formation. Several components have more than one function.

Explore related subjects

Biological Transport Blood Group Antigens Carrier Proteins Cell Adhesion Complement System Proteins Enzymes Erythrocyte Membrane Glycocalyx Humans Receptors, Cell Surface Journal Article Review

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

M E Reid, V Yahalom. 2000. Blood groups and their function.. https://doi.org/10.1053/beha.2000.0096

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

Inhibition of export of fibroblast growth factor-2 (FGF-2) from the prostate cancer cell lines PC3 and DU145 by Anvirzel and its cardiac glycoside component, oleandrin.

Anvirzel is an extract of Nerium oleander currently undergoing Phase I clinical evaluation as a potential treatment for cancer. Two of the active components of Anvirzel are the cardiac glycosides oleandrin and oleandrigenin. Previous studies have demonstrated that, in vitro, cardiac glycosides may inhibit fibroblast growth factor-2 (FGF-2) export through membrane interaction with the Na(+),K(+)-ATPase pump. In continuing research on the antitumor activity of this novel plant extract, the relative abilities of oleandrin and oleandrigenin to inhibit FGF-2 export from two human prostate cancer cell lines, DU145 and PC3, were examined. An ELISA assay was utilized to determine the FGF-2 concentration in the cell culture medium before and after exposure to cardiac glycosides or the parent extract material Anvirzel. Both cell lines were exposed to non-cytotoxic concentrations of oleandrin (0.05 and 0.1 ng/mL) for up to 72 hr. Studies also were conducted with Anvirzel and ouabain. Oleandrin (0.1 ng/mL) produced a 45.7% inhibition of FGF-2 release from PC3 cells and a 49.9% inhibition from DU145 cells. Non-cytotoxic concentrations (100 ng/mL) of Anvirzel produced a 51.9 and 30.8% inhibition of FGF-2 release, respectively, in the two cell lines. The decrease in FGF-2 release from cells required continuous incubation for 48--72 hr; shorter incubation times were not effective. These results demonstrate that Anvirzel, like oleandrin, inhibited FGF-2 export in vitro from PC3 and DU145 prostate cancer cells in a concentration- and time-dependent fashion and may, therefore, contribute to the antitumor activity of this novel treatment for cancer.

Biological Transport↗

PubMed2001

An experimental and theoretical study of the inhibition of Escherichia coli lac operon gene expression by antigene oligonucleotides.

Previously, we have developed a genetically structured mathematical model to describe the inhibition of Escherichia coli lac operon gene expression by antigene oligos. Our model predicted that antigene oligos targeted to the operator region of the lac operon would have a significant inhibitory effect on beta-galactosidase production. In this investigation, the E. coli lac operon gene expression in the presence of antigene oligos was studied experimentally. A 21-mer oligo, which was designed to form a triplex with the operator, was found to be able to specifically inhibit beta-galactosidase production in a dose-dependent manner. In contrast to the 21-mer triplex-forming oligonucleotide (TFO), several control oligos showed no inhibitory effect. The ineffectiveness of the various control oligos, along with the fact that the 21-mer oligo has no homology sequence with lacZYA, and no mRNA is transcribed from the operator, suggests that the 21-mer oligo inhibits target gene expression by an antigene mechanism. To simulate the kinetics of lac operon gene expression in the presence of antigene oligos, a genetically structured kinetic model, which includes transport of oligo into the cell, growth of bacteria cells, and lac operon gene expression, was developed. Predictions of the kinetic model fit the experimental data quite well after adjustment of the value of the oligonucleotide transport rate constant (9.0 x 10(-)(3) min(-)(1)) and oligo binding affinity constant (1.05 x 10(6) M(-)(1)). Our values for these two adjusted parameters are in the range of reported literature values.

Biological Transport↗

PubMed2001

Estrogen-derived steroidal metal complexes: agents for cellular delivery of metal centers to estrogen receptor-positive cells.

Targeted cellular delivery of drugs to specific tissues is an important goal in biomedical chemistry. Achieving this requires harnessing and applying molecular-level recognition events prevalent in (or specific to) the desired tissue type. Tissues rich in estrogen receptors (ERs), which include many types of breast cancer, accumulate molecules that have high binding affinities for these receptors. Therefore, molecules that (i) bind to the ER, (ii) have favorable cellular transport properties, and (iii) contain a second functionality (such as a center that may be used for diagnostic imaging or medical therapy) are exciting synthetic targets in the field of drug delivery. To this end, we have prepared a range of metallo-estrogens based on 17alpha-ethynylestradiol and examined their binding to the ER both as isolated receptor and in whole cell assays (ER positive MCF-7 cells). Estrogens functionalized with metal binding units are prepared by palladium-catalyzed cross-coupling reactions and a wide range of metal centers introduced readily. All the compounds prepared and tested exhibit effective binding to the estrogen receptor and are delivered across the cell membrane into MCF-7 cells. In the whole cell assays, despite their monocationic nature, the palladium and platinum complexes prepared exhibit similar (and even enhanced) receptor binding affinities compared to their corresponding neutral free ligands. It is unprecedented for a higher ER binding affinity to be observed for a cationic complex than for its metal-free ligand.

Biological Transport↗