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M M Kay

Publications and source records attributed to M M Kay.

At least 37 records · Page 2Linked to original sources
PubMed1991

Brain membrane protein band 3 performs the same functions as erythrocyte band 3.

We report the presence of band 3 protein(s) in mammalian brain that performs the same functions as those of erythroid band 3. These functions are anion transport, ankyrin binding, and generation of senescent cell antigen, an aging antigen that terminates the life of cells. Structural similarity of brain and erythroid band 3 is suggested by the reaction of antibodies to synthetic peptides of erythroid band 3 with brain band 3, the inhibition of anion transport by the same inhibitors, and an equal degree of inhibition of brain and erythrocyte anion transport by synthetic peptides of erythroid band 3 (pep-ANION 2, residues 588-602; pep-COOH, residues 812-827; pep-COOH-N6, residues 813-818). One of these segments, pep-COOH, contains antigenic determinants of senescent cell antigen. These findings suggest that the transport domains of erythroid and neural band 3 are similar functionally and structurally and support the hypothesis that the immunological mechanism of maintaining homeostasis is a general physiologic process for removing senescent and damaged cells in mammals and other vertebrates.

Amino Acid Sequence↗
PubMed1991

Hypothesis: synthetic aging antigen can be used to manipulate cellular lifespan.

Physiologic removal of old and damaged erythrocytes, platelets, and other terminally differentiated cells is initiated by the appearance of an aging antigen that marks them for death by initiating the binding of IgG autoantibody and subsequent removal by phagocytes. We have developed a synthetic aging antigen peptide that blocks binding of IgG to senescent cells in vitro. We hypothesize that the synthetic antigen can be used to prevent cell destruction in diseases such as autoimmune hemolytic anemias and idiopathic thrombocytopenia purpura, and that the antigen itself can be used to manipulate cellular lifespan in vivo.

Amino Acid Sequence↗
PubMed1991

Molecular mapping of human band 3 anion transport regions using synthetic peptides.

Band 3 is a ubiquitous membrane transport protein found in Golgi, mitochondrial, nuclear, and cell membranes. It is the most heavily used anion transport system in the body because it is responsible for CO2 exchange in all tissues and organs and for acid-base balance. The anion transport regions are mapped along the band 3 molecule using synthetic peptides (pep) from extracellular regions of band 3 and/or suspected anion transport regions. Assays include anion transport/inhibition and immunoblotting with anti-idiotypic antibodies to a transport inhibitor. Results indicate that anion binding/transport regions of band 3 reside within residues 549-594, (588-594 being the most active) and 804-839 (822-839 being the most active), and 869-883. Pep-COOH (residues 812-827), which is part of senescent cell antigen, is an anion binding site with most of the activity localized to residues 813-818 (the six amino acids on the amino side of pep-COOH). The stilbene disulfonate inhibitors of transport bind to peptide 812-830, and possibly peptides 788-805 and 800-818, as determined with anti-idiotypic antibodies. Residues 538-554, which have been reported to be a transport segment of band 3, do not bind sulfate. Band 3 external loops containing residues 539-553 and 812-830, and internal segments containing residues 588-594 and 869-883, are in close spacial proximity in the membrane. The contribution of lysine and/or arginine to anion transport is examined by synthesizing peptides in which glycines or arginines are substituted for lysines or arginines. Lysines can contribute to anion binding but are not required.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1991

Band 3 in aging and neurological disease.

Senescent cell antigen appears on old cells and marks them for death by initiating the binding of IgG autoantibody and subsequent removal by phagocytes in mammals and other vertebrates. We have created a synthetic aging antigen that blocks binding of IgG to senescent cells in vitro. Synthetic senescent cell antigen might be effective in preventing cellular destruction in vivo in certain diseases, and can be used to manipulate cellular life span in situ. Senescent cell antigen is generated by the modification of an important structural and transport membrane molecule, protein band 3. Band 3 is present in cellular, nuclear, Golgi, and mitochondrial membranes as well as in cell membranes. Band 3 proteins in nucleated cells participate in cell surface patching and capping. Band 3 maintains acid-base balance by mediating the exchange of anions (e.g., chloride, bicarbonate), and is the binding site for glycolytic enzymes. It is responsible for CO2 exchange in all tissues and organs. Thus, it is the most heavily used anion transport system in the body. Band 3 is a major transmembrane structural protein which attaches the plasma membrane to the internal cell cytoskeleton by binding to band 2.1 (ankyrin). Oxidation generates senescent cell antigen in situ. Band 3 is present in the central nervous system, and differences have been described in band 3 between young and aging brain tissue. One autosomal recessive neurological disease, choreoacanthocytosis, is associated with band 3 abnormalities. The 150 residues of the carboxyl terminus segment of band 3 appear to be altered. In brains from Alzheimer's disease patients, antibodies to aged band 3 label the amyloid core of classical plaques and the microglial cells located in the middle of the plaque in tissue sections, and an abnormal band 3 in immunoblots. Band 3 protein(s) in mammalian brain performs the same functions as that of erythroid band 3. These functions is anion transport, ankyrin binding, and generation of senescent cell antigen, an aging antigen that terminates the life of cells. Structural similarity of brain and erythroid band 3 is suggested by the reaction of antibodies to synthetic peptides of erythroid band 3 with brain band 3, the inhibition of anion transport by the same inhibitors, and an equal degree of inhibition of brain and erythrocyte anion transport by synthetic peptides of erythroid band 3. One of these segments, pep-COOH, contains antigenic determinants of senescent cell antigen.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗
PubMed1991

Drosophila to bacteriophage to erythrocyte: the erythrocyte as a model for molecular and membrane aging of terminally differentiated cells.

Senescent cell antigen appears on old cells and marks them for death by initiating the binding of IgG autoantibody and subsequent removal by phagocytes in mammals and other vertebrates. Although the initial studies are done using erythrocytes as a model, senescent cell antigen has been found on all cells examined. Oxidation generates senescent cell antigen in situ. Senescent cell antigen is generated by the modification of an important structural and transport membrane molecule, protein band 3. Band 3 is a ubiquitous protein. It is present in cell, nuclear, Golgi, and mitochondrial membranes. Band 3 is the most heavily used anion exchanger in the human body because of its crucial role in respiration and acid-base balance. Senescent cell antigen has been localized to band 3 residues 538-554 and 812-827, using competitive inhibition studies with synthetic peptides of band 3 to absorb the IgG isolated from senescent erythrocytes and immunoblotting studies. In mammalian brain, band 3 performs the same functions as that of erythroid band 3. These functions are anion transport, ankyrin binding, and generation of senescent cell antigen, an aging antigen that terminates the life of cells. Our results suggest that the transport domain of erythroid and neural band 3 are similar functionally and structural. This supports the hypothesis that the immunological mechanism of maintaining homeostasis is a general physiologic process for removing senescent and damaged cells in mammals and other vertebrates.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1990

Membrane channel protein abnormalities and autoantibodies in neurological disease.

Immunological analogues of band 3, the anion transporter of the human erythrocyte, have been identified in all cells, including both isolated neurons and neurons of the central nervous system. We hypothesized that the anion channel is altered in neurological disease associated with choreiform movements because gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in mammalian brain, binds to its receptor and opens an integral membrane chloride channel. In order to examine this hypothesis, we studied a family with a serious, progressive, genetic neurologic disorder with acanthocytosis (choreoacanthocytosis) that resembles Huntington's chorea. We selected choreoacanthocytosis because erythrocytes, which are readily obtained, are affected in this disease as well as the central nervous system. Biochemical studies of erythrocytes from the proposita, mother, and brother revealed that sulfate transport Vmax was increased, and glucose efflux was decreased. Erythrocytes exhibited immunological changes indicative of cellular aging/transporter damage. In addition, transporter reactive antibodies were present. This is the first evidence for abnormalities of membrane transport in this neurologic disorder.

Acanthocytes↗
PubMed1990

Definition of a physiologic aging autoantigen by using synthetic peptides of membrane protein band 3: localization of the active antigenic sites.

Senescent cell antigen (SCA), an aging antigen, is a protein that appears on old cells and marks them for removal by the immune system in mammals. It is derived from band 3, a ubiquitous membrane transport protein found in diverse cell types and tissues. We have used synthetic peptides to identify aging antigenic sites on band 3, using a competitive inhibition assay and immunoblotting with IgG directed against the aging antigen on old cells. Results indicate that: (i) the active antigenic sites of the aging antigen reside on membrane protein band 3 residues that are extracellular regions implicated in anion transport (residues 538-554 and 788-827); (ii) a putative ankyrin-binding-region peptide is not involved in SCA activity; and (iii) carbohydrate moieties are not required for the antigenicity or recognition of SCA because synthetic peptides alone abolish binding of senescent cell IgG to erythrocytes. One of the putative transport sites that contributes to the aging antigen is located toward the carboxyl terminus. A model of band 3 is presented. Localization of the active antigenic site on the band 3 molecule facilitates definition of the molecular changes occurring during aging that initiate molecular as well as cellular degeneration.

Amino Acid Sequence↗
PubMed1990

Alterations of band 3 transport protein by cellular aging and disease: erythrocyte band 3 and glucose transporter share a functional relationship.

Structural changes in human erythrocyte band 3 that affect anion transport are correlated with changes in glucose transport in situ. Breakdown of band 3, observed during normal erythrocyte aging in situ and in some diseases involving erythrocytes, is associated with an increase in Km and a decrease in Vmax of sulfate self-exchange, and with an increase in Km and Vmax of glucose efflux. Erythrocytes containing a high molecular weight form of band 3 exhibit an increase in Vmax of sulfate exchange and a decrease in Vmax of glucose efflux. Identical transport characteristics are observed in abnormal band-3-containing erythrocytes from individuals with familial amyotrophic chorea with acanthocytosis. A third band 3 alteration, fast-aging band 3, exhibits decreased Vmax of sulfate exchange and an increase in Km and decrease in Vmax of glucose efflux. Changes in band 3 structure that are the result of unstable hemoglobin or a deficiency in glucose-6-phosphate dehydrogenase and that do not affect anion transport have no effect on glucose transport characteristics. These data indicate the existence of a functional relationship between the membrane-spanning, anion-transport domain of band 3 and glucose transport in human erythrocytes. Antibodies to synthetic peptides reveal structural changes in membranes from the three inborn band 3 alterations and in band 3 itself in membranes from fast-aging band 3. Thus, immunological data suggests a structural relationship between anion and glucose transporters.

Amino Acid Sequence↗
PubMed1990

Molecular mapping of the active site of an aging antigen: senescent cell antigen requires lysine(s) for antigenicity and is located on an anion-binding segment of band 3 membrane transport protein.

An aging antigen, senescent cell antigen, resides on the 911 amino acid membrane protein band 3. It marks cells for removal by initiating specific IgG binding. The active antigenic sites of the aging antigen have been localized to residues 538-554 and 778-827. Two peptides within these regions interact synergistically to generate a synthetic aging antigen that is an effective inhibitor of senescent cell IgG binding to old cells. We synthesized peptides corresponding to these residues (pep-ANION 1: SKLIKIFQDHPLQKTYN, and pep-COOH: LFKPPKYHPDVPYVKR). These are extracellular regions of band 3 containing lysines which are implicated in anion transport. The contribution of lysine to the antigenicity of the aging antigen and to anion transport was examined by chemically modifying the lysines on both synthetic peptides and whole cells, and by synthesizing peptides in which glycines or arginines were substituted for lysines. Anion transport sites were localized using 16- to 18-mer peptides followed by 6- to 8-mer peptides. Functional studies with the peptide pep-COOH indicate that it contains sulfate-binding sites and inhibits sulfate transport in addition to carrying aging antigenic determinants. Substitution of arginines or glycines for lysines in pep-COOH reduces the sulfate-binding properties of the peptide although significant inhibition still occurs. Residues 812-827 (pep-COOH) and 813-818 (N6, the six amino acids on the amino side of pep-COOH) and 822-839 are inhibitors of anion transport when used in equimolar amounts with sulfate suggesting that these regions may be transport regions in situ. Results of this study indicate that: (a) lysines are required for the integrity of the aging antigenic site; (b) pep-COOH (residues 812-827) is part of senescent cell antigen and an anion-binding site; (c) pep-ANION 1 (538-554), which has been reported to be a transport segment of band 3, does not bind sulfate; (d) residues 588-602 are part of an anion binding/transport segment; (e) band 3 residues 822-839 are part of an anion binding/transport site, and (f) lysines contribute to anion binding but are not the only amino acid(s) required for anion binding and, thus, anion transport.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1990

Membrane protein band 3 alteration associated with neurologic disease and tissue-reactive antibodies.

Immunological analogues of band 3, the anion transporter, have been identified in all cells that have been studied, including both isolated neurons and neurons of the central nervous system. We studied band 3 structural/functional relationships in a family in which the proposita has a serious, progressive, genetic neurologic disorder with acanthocytosis (choreoacanthocytosis). Biochemical studies of erythrocytes from the proposita, her mother and brother revealed that maximal sulfate transport velocity (Vmax) and sodium transport were increased, glucose efflux was decreased. Ankyrin binding was normal. Immunologic studies revealed increased IgG binding to middle-aged cells of the proposita and her brother, binding of antibodies to aged band 3 to a distinct region of band 3 in erythrocyte membranes in immunoblots, and binding of choreoacanthocytosis sera IgG to erythroid and brain band 3 and synthetic peptides of band 3 in immunoblots. Antibodies to neural and, to a lesser extent, renal tissue were observed in choreoacanthocytosis sera. These antibodies appear to have a band 3 specificity. Monoclonal antibodies to 150 residues of the carboxyl terminus of band 3 stained two band 3 fragments in immunoblots of chymotrypsin-digested membranes that are not present in control cells. This suggests that band 3 is altered in this autosomal recessive neurologic disorder. In addition, these monoclonal antibodies stained five band 3 breakdown products in membranes of untreated red cells in both control and choreoacanthocytosis cells. The possibility that a disturbance of some function of band 3 may contribute to the neurologic abnormalities in affected individuals is intriguing. This is the first evidence for abnormalities of membrane transport in the neurologic disorder known as choreoacanthocytosis.

Acanthocytes↗
PubMed1990

Senescent cell antigen, band 3, and band 3 mutations in cellular aging.

As part of our ongoing studies on mechanisms of cellular aging, we searched for "experiments of nature" that might provide insights into the process of normal cellular aging. Our search for band 3 protein alterations resulted in the discovery of three different ones. A band 3 alteration that results from an addition to band 3 does not alter red cell lifespan or produce clinical disease. In contrast, two band 3 alterations that are associated with band 3 aging and/or degradation are characterized by shortened red cell lifespan and clinical diseases.

Antigens, Differentiation↗
PubMed1989

Alteration in membrane protein band 3 associated with accelerated erythrocyte aging.

We report a human band 3 alteration that is associated with anemia as determined by a reticulocyte count of 20%. Erythrocyte defects included increased IgG binding, increased breakdown products of band 3, and altered anion- and glucose-transport activity in middle-aged cells. These changes were observed during normal erythrocyte aging in situ. Binding of ankyrin to band 3 was normal. Serum/cell crossover studies indicated that a neoantigen appears on the propositus' erythrocytes to which IgG from both propositus and control serum binds as measured with a protein A binding assay. IgG eluted from the propositus' erythrocytes appeared to have a specificity for senescent cell antigen as determined by a phagocytosis inhibition assay. Immunoelectron microscopy showed that antibodies to band 3, which do not normally bind to intact erythrocytes, bound to the propositus' erythrocytes. Antibody 980 binds to normal old cells but not young or middle-aged cells. It also binds to a distinct region of band 3 in immunoblots of membranes from the propositus' middle-aged cells. Cells from both of the propositus' parents exhibited increased IgG binding and altered anion and glucose transport. The results of these studies suggest that (i) band 3 is aging prematurely in erythrocytes from the propositus, (ii) senescent cell antigen appears on the propositus' middle-aged red cells, and (iii) band 3 alterations observed in the propositus may have a genetic component.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1988

Functional topography of band 3: specific structural alteration linked to functional aberrations in human erythrocytes.

Band 3 is the major anion transport polypeptide of erythrocytes. It appears to be the binding site of several glycolytic enzymes. Structurally, band 3 is the major protein spanning the erythrocyte membrane and connects the plasma membrane to band 2.1, which binds to the cytoskeleton. In the present study, we report an alteration of band 3 molecule that is associated with the following changes: erythrocyte shape change from discoid to "thorny cells" (acanthocytes), restriction of rotational diffusion of band 3 in the membrane, increase in anion transport, and decrease in the number of high-affinity ankyrin-binding sites. Changes in erythrocyte IgG binding, glyceraldehyde-3-phosphate dehydrogenase, fluorescence polarization (indicative of membrane fluidity), and other membrane proteins as determined by polyacrylamide gel electrophoresis were not detected. Cells containing the altered band 3 polypeptide were obtained from individuals with abnormal erythrocyte morphology. Two-dimensional peptide maps revealed differences in the Mr 17,000 anion transport segment of band 3 consistent with additions of tyrosines or tyrosine-containing peptides. The data suggest that (i) this alteration of band 3 does not result in accelerated aging as does cleavage and (ii) structural changes in the anion transport region result in alterations in anion transport.

Acanthocytes↗
PubMed1988

Band-3 polymers and aggregates, and hemoglobin precipitates in red cell aging.

As part of our systematic ongoing studies of mechanisms of cellular and molecular aging, we developed a "biochemical profile" of senescent human red cells. This "red cell aging" panel allows us to assess functional red cell age independent of chronologic age. The panel used to obtain this profile includes IgG binding, phagocytosis, enzyme activity, anion transport, ankyrin binding, and immunoblotting with antibodies to band 3. We used this panel to compare the biochemical profile of glucose 6-phosphate dehydrogenase-deficient and hemoglobin Köln cells containing high molecular weight protein polymers or hemoglobin precipitates with that of normal senescent cells. We found no evidence in support of the concept that aggregation of band 3 plays a role in the mechanism for generating senescent cell antigen. Observations such as these support the hypothesis that degradation of band 3, rather than aggregation is a critical event in IgG binding and normal erythrocyte aging.

Anion Exchange Protein 1, Erythrocyte↗