scholarly journals Comparison of serum anti-band 3 and anti-Gal antibody binding to density-separated human red blood cells

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 628-636 ◽  
Author(s):  
MP Sorette ◽  
U Galili ◽  
MR Clark
Keyword(s):  
Quantitative Relationship ◽  
Band 3 ◽  
T Antigen ◽  
Low Ph ◽  
High Density ◽  
Structure Characteristic ◽  
Binding Studies ◽  
Serum Antibodies ◽  
Human Rbcs

Abstract This study examines the quantitative relationship between two natural serum antibodies, anti-band 3 and anti-alpha-galactosyl (anti-Gal), in their capacity to bind to human red blood cell (RBC) populations separated on density gradients. The question was approached in two ways. First, we determined the extent of rebinding of affinity-purified human serum antibodies to RBCs that had been stripped of in situ antibody. Second, we eluted the in situ bound antibody at low pH from density-separated RBCs and determined the proportion of total eluted antibody that bound specifically to erythrocyte band 3 or to a Gal- alpha-(1,3)-Gal structure. Our results show that high-density human RBCs bind increased amounts of both antibodies. Anti-Gal rebinding was specific, because it was saturable and occurred in the presence of serum IgG depleted of anti-Gal. Binding assays using control natural autoantibodies directed against antigens not found on the RBC surface showed that high-density RBCs also bind increased amounts of these antibodies as compared with low-density RBCs. However, the extent of this binding is substantially lower than that of anti-band 3 and anti- Gal. Binding studies using the lectins Bandeiraea Simplicifolia (alpha- galactosyl specific) and Arachis Hypogaea (peanut agglutinin, beta- galactosyl specific) indicated that only the alpha-galactosyl sites are exposed on high density RBCs, and not the beta-galactosyl structure characteristic of T antigen. Antibody that is eluted at low pH from high density RBCs contains a 5.0% to 18.0% component that binds to band 3 protein, and a 9.1% to 39.0% component that recognizes the alpha- galactosyl structure. Together, the two antibodies appear to constitute an average of 35% (range 17.2% to 57.4%) of the in situ bound antibody from high-density human RBCs.

scholarly journals Comparison of serum anti-band 3 and anti-Gal antibody binding to density-separated human red blood cells

Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 628-636
Author(s):  
MP Sorette ◽  
U Galili ◽  
MR Clark
Keyword(s):  
Quantitative Relationship ◽  
Band 3 ◽  
T Antigen ◽  
Low Ph ◽  
High Density ◽  
Structure Characteristic ◽  
Binding Studies ◽  
Serum Antibodies ◽  
Human Rbcs

This study examines the quantitative relationship between two natural serum antibodies, anti-band 3 and anti-alpha-galactosyl (anti-Gal), in their capacity to bind to human red blood cell (RBC) populations separated on density gradients. The question was approached in two ways. First, we determined the extent of rebinding of affinity-purified human serum antibodies to RBCs that had been stripped of in situ antibody. Second, we eluted the in situ bound antibody at low pH from density-separated RBCs and determined the proportion of total eluted antibody that bound specifically to erythrocyte band 3 or to a Gal- alpha-(1,3)-Gal structure. Our results show that high-density human RBCs bind increased amounts of both antibodies. Anti-Gal rebinding was specific, because it was saturable and occurred in the presence of serum IgG depleted of anti-Gal. Binding assays using control natural autoantibodies directed against antigens not found on the RBC surface showed that high-density RBCs also bind increased amounts of these antibodies as compared with low-density RBCs. However, the extent of this binding is substantially lower than that of anti-band 3 and anti- Gal. Binding studies using the lectins Bandeiraea Simplicifolia (alpha- galactosyl specific) and Arachis Hypogaea (peanut agglutinin, beta- galactosyl specific) indicated that only the alpha-galactosyl sites are exposed on high density RBCs, and not the beta-galactosyl structure characteristic of T antigen. Antibody that is eluted at low pH from high density RBCs contains a 5.0% to 18.0% component that binds to band 3 protein, and a 9.1% to 39.0% component that recognizes the alpha- galactosyl structure. Together, the two antibodies appear to constitute an average of 35% (range 17.2% to 57.4%) of the in situ bound antibody from high-density human RBCs.

scholarly journals Millisecond lattice gasification for high-density CO2- and O2-sieving nanopores in single-layer graphene

2021 ◽  
Vol 7 (9) ◽  
pp. eabf0116
Author(s):  
Shiqi Huang ◽  
Shaoxian Li ◽  
Luis Francisco Villalobos ◽  
Mostapha Dakhchoune ◽  
Marina Micari ◽  
...  
Keyword(s):  
Single Layer ◽  
High Density ◽  
Single Layer Graphene ◽  
Pore Density ◽  
Vacancy Defects ◽  
Carbon Gasification ◽  
Layer Graphene ◽  
Gas Molecules ◽  
Good Agreement

Etching single-layer graphene to incorporate a high pore density with sub-angstrom precision in molecular differentiation is critical to realize the promising high-flux separation of similar-sized gas molecules, e.g., CO2 from N2. However, rapid etching kinetics needed to achieve the high pore density is challenging to control for such precision. Here, we report a millisecond carbon gasification chemistry incorporating high density (>1012 cm−2) of functional oxygen clusters that then evolve in CO2-sieving vacancy defects under controlled and predictable gasification conditions. A statistical distribution of nanopore lattice isomers is observed, in good agreement with the theoretical solution to the isomer cataloging problem. The gasification technique is scalable, and a centimeter-scale membrane is demonstrated. Last, molecular cutoff could be adjusted by 0.1 Å by in situ expansion of the vacancy defects in an O2 atmosphere. Large CO2 and O2 permeances (>10,000 and 1000 GPU, respectively) are demonstrated accompanying attractive CO2/N2 and O2/N2 selectivities.

scholarly journals Identification and characterization of a second 4,4′-dibenzamido-2,2′-stilbenedisulphonate (DBDS)-binding site on band 3 and its relationship with the anion/proton co-transport function

2005 ◽  
Vol 388 (1) ◽  
pp. 343-353 ◽  
Author(s):  
James M. SALHANY ◽  
Karen S. CORDES ◽  
Renee L. SLOAN
Keyword(s):  
Binding Site ◽  
Proton Transport ◽  
Chloride Concentration ◽  
Band 3 ◽  
Low Ph ◽  
Binding Mechanism ◽  
Access Channel ◽  
Binding Kinetic ◽  
Transport Site

Band 3 mediates both electroneutral AE (anion exchange) and APCT (anion/proton co-transport). Protons activate APCT and inhibit AE with the same pK (∼5.0). SDs (stilbenedisulphonates) bind to a primary, high-affinity site on band 3 and inhibit both AE and APCT functions. In this study, we present fluorescence and kinetic evidence showing that lowering the pH activates a second site on band 3, which binds DBDS (4,4′-dibenzamido-2,2′-stilbenedisulphonate) independently of chloride concentration, and that DBDS binding to the second site inhibits the APCT function of band 3. Activation of the second site correlated with loss of chloride binding to the transport site, thus explaining the lack of competition. The kinetics of DBDS binding at the second site could be simulated by a slow-transition, two-state exclusive binding mechanism (R0↔T0+D↔TD↔RD, where D represents DBDS, R0 and T0 represent alternate conformational states at the second DBDS-binding site, and TD and RD are the same two states with ligand DBDS bound), with a calculated overall Kd of 3.9 μM and a T0+D↔TD dissociation constant of 55 nM. DBDS binding to the primary SD site inhibited approx. 94% of the proton transport at low pH (KI=68.5±11.8 nM). DBDS binding to the second site inhibited approx. 68% of the proton transport (KI=7.27±1.27 μM) in a band 3 construct with all primary SD sites blocked through selective cross-linking by bis(sulphosuccinimidyl)suberate. DBDS inhibition of proton transport at the second site could be simulated quantitatively within the context of the slow-transition, two-state exclusive binding mechanism. We conclude that band 3 contains two DBDS-binding sites that can be occupied simultaneously at low pH. The binding kinetic and transport inhibition characteristics of DBDS interaction with the second site suggest that it may be located within a gated access channel leading to the transport site.

scholarly journals Specificity and VH sequence of two monoclonal antibodies against the N-terminus of dystrophin

1995 ◽  
Vol 309 (1) ◽  
pp. 355-359 ◽  
Author(s):  
G E Morris ◽  
C Nguyen ◽  
Nguyen thi Man
Keyword(s):  
Monoclonal Antibodies ◽  
Point Mutations ◽  
Hypervariable Region ◽  
Variable Region ◽  
Binding Studies ◽  
Cdna Sequences ◽  
N Terminus ◽  
Random Library ◽  
Blast Cells

We have used a random library of 15-mer peptides expressed on phage to show that two monoclonal antibodies (mAbs) require only the first three amino acids of dystrophin (Leu-Trp-Trp) for binding. Since the mAbs recognize dystrophin in frozen muscle sections, the results suggest that this hydrophobic N-terminus of dystrophin is accessible to antibody in situ. Quantitative binding studies suggested minor differences in specificity between the two mAbs, so the Ig heavy-chain variable region (VH) sequences of the two hybridomas were determined by RT-PCR and cDNA sequencing. After elimination of PCR errors, the two cDNA sequences were found to be identical except for five somatic mutations which resulted in three amino acid changes in the second hypervariable region (CDR2). The results suggest that the two hybridomas originated from the same lymphocyte clone in a germinal centre of the spleen, but underwent different point mutations and subtype switches during clonal expansion to form blast cells.

Control of Hierarchically Ordered Positive and Negative Replicas of Wood Cellular Structures by Surfactant-Directed Sol-Gel Mineralization

2002 ◽  
Vol 726 ◽  
Author(s):  
Yongsoon Shin ◽  
Jun Liu ◽  
Li-Qiong Wang ◽  
Jeong Ho Chang ◽  
William D. Samuels ◽  
...  
Keyword(s):  
Silicic Acid ◽  
Cell Walls ◽  
Cellular Structure ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Silica Particles ◽  
Low Ph ◽  
Cellular Structures ◽  
Inner Surface

AbstractWe here report the synthesis of ordered ceramic materials with hierarchy produced by an in-situ mineralization of ordered wood cellular structures with surfactant-templated sol-gel at different pH. At low pH, a silicic acid is coated onto inner surface of wood cellular structure and it penetrates into pores left, where degraded lignin and hemicellulose are leached out, to form a positive replica, while at high pH the precipitating silica particles due to fast condensation clog the cells and pit structures to form a negative replica of wood. The calcined monoliths produced in different pHs contain ordered wood cellular structures, multi-layered cell walls, pits, vessels well-preserved with positive or negative contrasts, respectively. The surfactant-templated mineralization produces ordered hexagonal nanopores with 20Å in the cell walls after calcination.

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

1990 ◽  
Vol 68 (12) ◽  
pp. 1419-1427 ◽  
Author(s):  
Gieljan J. C. G. M. Bosman ◽  
Marguerite M. B. Kay
Keyword(s):  
Glucose Transport ◽  
Structural Changes ◽  
Glucose Transporter ◽  
Functional Relationship ◽  
Band 3 ◽  
Anion Transport ◽  
Cellular Aging ◽  
Abnormal Band ◽  
Membrane Spanning

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.Key words: red cell, anion transport, membrane proteins, aging, choreoacanthocytosis, anemia.

Development of heavyweight aggregate via in-situ growth of high density ceramics using red mud

2021 ◽  
Vol 313 ◽  
pp. 125376
Author(s):  
Ashutosh Singh Raghubanshi ◽  
Manish Mudgal ◽  
Anil Kumar ◽  
R.K. Chouhan ◽  
Avanish Kumar Srivastava
Keyword(s):  
Red Mud ◽  
High Density ◽  
In Situ Growth

EFFECTS OF GROWING SEASON SOIL TEMPERATURE, MOISTURE, AND NH4-N ON SOIL NITROGEN

1974 ◽  
Vol 54 (4) ◽  
pp. 403-412 ◽  
Author(s):  
C. A. CAMPBELL ◽  
D. W. STEWART ◽  
W. NICHOLAICHUK ◽  
V. O. BIEDERBECK
Keyword(s):  
Quantitative Relationship ◽  
Growing Season ◽  
Stepwise Multiple Regression ◽  
Soil N ◽  
N Transformations ◽  
Temperature Changes ◽  
Diurnal Patterns ◽  
Multiple Regression Technique ◽  
Time Required

Wood Mountain loam was wetted with water or (NH4)2SO4 solution to provide a factorial combination among three moisture and three NH4-N levels. Samples in polyethylene bags were incubated at 2.5-cm depths in fallow, and in an incubator that simulated the diurnal patterns of temperature fluctuation recorded in the field. During the growing season, treatments were sampled regularly for moisture, NO3− and exchangeable NH4-N. Similar determinations were made on in situ samples taken in fallow Wood Mountain loam. The incubator simulated the effects of growing season temperatures on soil N transformations satisfactorily. Pronounced increases or decreases in temperature led to flushes in N mineralization. However, in the 1972 growing season, temperature was suboptimal and temperature changes were generally small. Consequently, when a stepwise multiple regression technique was used to analyze the data, neither ammonification nor nitrification showed a quantitative relationship to temperature. Comparison of the nitrification occurring in laboratory-incubated soils with that occurring in situ led to the conclusion that 70 to 90% of the NO3-N produced in surface soil resulted from wetting and drying. Estimates of potentially ammonifiable soil N(No) and its rate of mineralization (k) were derived from cumulative ammonification by assuming that the laws of first-order kinetics were applicable. In the 10, 15, and 20% moisture treatments the average No was 27, 41, and 82 ppm, respectively. Under the conditions of this study, the time required to mineralize half of No was about 7 wk.

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