Inhibition of phosphate transport across the human erythrocyte membrane by chemical modification of sulfhydryl groups

Yamaguchi, Takeo; Kimoto, Eiji

doi:10.1021/bi00122a010

Cited by 20 publications

(3 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The site of conformational change of the dimeric cytoplasmic domain due to hemoglobin binding is believed to be the cluster of sulfhydryl groups that lie ~100 A from the N-terminus as shown by measuring sulfhydryl reactivity on hemoglobin binding (Salhany & Cassoly, 1989). Further, it has been reported that chemical modification of the sulfhydryl groups in the cytoplasmic domain of band 3 inhibits phosphate transport across the human eryhtrocyte membrane (Yamaguchi & Kimoto, 1992). This model for conformational changes in the cytoplasmic domain transmitted to the TMD causing changes in the transport activity of the TMD gives support to the view that band 4.2 could act as a modulator of anion transport by band 3 by acting through the cytoplasmic domain.…”

Section: Transport Studiesmentioning

confidence: 69%

A role for band 4.2 in human erythrocyte band 3 mediated anion transport

Malik¹,

Sami²,

Watts³

1993

Biochemistry

View full text Add to dashboard Cite

Human erythrocyte band 3 was purified essentially free of peripheral proteins, in particular band 4.2, using affinity chromatography. Band 3 protein was then reconstituted into liposomes of lipid type and ratio approximating that of erythrocyte membranes. Stilbenedisulfonate inhibition of band 3 mediated efflux of radiolabeled sulfate from preloaded liposomes was used to test the functionality and correct orientation of the protein. When sulfate efflux, mediated by purified band 3, was compared with partially purified band 3, which contained detectable amounts of bands 4.1 and 4.2, a clear difference in efflux was measured. Sulfate efflux was approximately 30% faster from liposomes containing purified band 3 compared with those containing partially purified protein. In order to investigate further any specific effect of band 4.2 protein on band 3 mediated anion transport, band 4.2 was purified. Increasing amounts of band 4.2 were complexed with purified band 3 and then reconstituted into liposomes. Increasing amounts of band 4.2 complexed with band 3 caused a decrease in band 3 mediated anion transport. The effect of band 4.2 on band 3 mediated anion transport appears to be specific since increasing concentrations of band 4.2 added exogenously to band 3 in reconstituted vesicles (rather than complexed with band 3 before reconstitution) produced no significant changes in sulfate efflux. Further, when increasing amounts of band 4.2 were added to the functionally active transmembrane domain of band 3 and then reconstituted into vesicles, there was also no significant change in sulfate efflux.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

Section: Transport Studiesmentioning

confidence: 69%

A role for band 4.2 in human erythrocyte band 3 mediated anion transport

Malik¹,

Sami²,

Watts³

1993

Biochemistry

View full text Add to dashboard Cite

show abstract

“…Casey and coworkers (255, 366-368) have used cysteineless band 3 for informative studies of topology and function by cysteine scanning mutagenesis, as reviewed by Reithmeier et al (20). Despite the fact that band 3 has no cysteine residues that are necessary for transport, treatment with N-ethylmaleimide (NEM) or oxidative stress inhibits red cell anion transport to varying degrees (369)(370)(371)(372)(373)(374)(375).…”

Section: Effects Of Oxidative Stress Thiol Status and Tyrosine Phosphorylationmentioning

confidence: 99%

Cell physiology and molecular mechanism of anion transport by erythrocyte band 3/AE1

Jennings

2021

American Journal of Physiology-Cell Physiology

View full text Add to dashboard Cite

The major transmembrane protein of the red blood cell, known as band 3, AE1, and SLC4A1, has two main functions: 1) catalysis of Cl-/HCO3- exchange, one of the steps in CO2 excretion; 2) anchoring the membrane skeleton. This review summarizes the 150 year history of research on red cell anion transport and band 3 as an experimental system for studying membrane protein structure and ion transport mechanisms. Important early findings were that red cell Cl- transport is a tightly coupled 1:1 exchange and band 3 is labeled by stilbenesulfonate derivatives that inhibit anion transport. Biochemical studies showed that the protein is dimeric or tetrameric (paired dimers) and that there is one stilbenedisulfonate binding site per subunit of the dimer. Transport kinetics and inhibitor characteristics supported the idea that the transporter acts by an alternating access mechanism with intrinsic asymmetry. The sequence of band 3 cDNA provided a framework for detailed study of protein topology and amino acid residues important for transport. The identification of genetic variants produced insights into the roles of band 3 in red cell abnormalities and distal renal tubular acidosis. The publication of the membrane domain crystal structure made it possible to propose concrete molecular models of transport. Future research directions include improving our understanding of the transport mechanism at the molecular level and of the integrative relationships among band 3, hemoglobin, carbonic anhydrase, and gradients (both transmembrane and subcellular) of HCO3-, Cl-, O2, CO2, pH, and NO metabolites during pulmonary and systemic capillary gas exchange.

show abstract

“…The importance of thiol groups for the function of numerous proteins involved in transport processes has been well demonstrated. Thiol dependent transporters include the vacuolar ATPase [5], the Ca# + pump ATPase [6], simple channels for water and urea [7,8], gated chloride dependent K + channel flux [9], and a variety of mobile carriers for glucose [10,11], nucleosides [12], choline [13], phosphate [14][15][16], amino acids [17], fatty acids [18], anions [18,19] and cations [20]. However, in earlier studies using lysosomal membrane vesicles the sulphate transporter did not appear to be particularly dependent upon sulphydryl (thiol) groups as NEM had no effect on trans-stimulation of sulphate transport [1].…”

Section: Introductionmentioning

confidence: 99%

Lysosomal sulphate transport is dependent upon sulphydryl groups

Chou

Passage

Jonas

1998

Biochemical Journal

View full text Add to dashboard Cite

Using thiol blocking agents, we examined the role of sulphydryl groups for function of the lysosomal sulphate transport system. Monothiol binding reagents, p-hydroxymercuribenzoic acid (p-HMB) and p-chloromercuribenzene sulphonic acid (p-CMBS), dithiol binding reagents such as CuCl2, the alkylating agent, N-ethylmaleimide (NEM), and NADH all inhibited lysosomal sulphate transport. The inhibitory effects of NEM and Cu2+ were not additive, suggesting that they both act upon the same critical sulphydryl group(s). Unlike the case for NEM, the inhibitory effects of Cu2+ were reversed by the reducing agent, dithiothreitol. Exposure to NEM resulted in a seven-fold increase in Km to 867 microM versus a control value of 126 microM and a modest decrease in Vmax to 99 pmolperunit beta-hexosaminidase per 30 s versus a control value of 129 pmolperunit beta-hexosaminidase per 30 s. Similar although somewhat less dramatic results were obtained using Cu2+ with an increase of Km to 448 microM and a Vmax of 77 pmolperunit beta-hexosaminidase per 30 s. The sulphate transport activity of detergent solubilized lysosomal membranes could be bound to a p-chloromercuribenzoic acid (p-CMB)-Sepharose sulphydryl affinity resin and eluted with mercaptoethanol. Sulphydryl groups thus appear to play a role in sulphate transport through effects on substrate affinity. Sulphydryl-binding appears to be a strategy that may be useful for purification of the transporter.

show abstract

Inhibition of phosphate transport across the human erythrocyte membrane by chemical modification of sulfhydryl groups

Cited by 20 publications

References 41 publications

A role for band 4.2 in human erythrocyte band 3 mediated anion transport

A role for band 4.2 in human erythrocyte band 3 mediated anion transport

Cell physiology and molecular mechanism of anion transport by erythrocyte band 3/AE1

Lysosomal sulphate transport is dependent upon sulphydryl groups

Contact Info

Product

Resources

About