PMID- 9774471
OWN - NLM
STAT- MEDLINE
DCOM- 19981112
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 273
IP  - 43
DP  - 1998 Oct 23
TI  - Carbonic anhydrase II binds to the carboxyl terminus of human band 3, the 
      erythrocyte C1-/HCO3- exchanger.
PG  - 28430-7
AB  - In this study, we provide evidence that the 33-residue carboxyl-terminal (Ct) 
      region of the human erythrocyte chloride/bicarbonate exchanger, band 3, binds 
      carbonic anhydrase II (CAII). Immunofluorescence showed that tomato 
      lectin-mediated clustering of band 3 in ghost membranes caused a similar 
      clustering of CAII, indicating an in situ association. CAII cosolubilized and 
      coimmunoprecipitated with band 3, suggesting that the two proteins form a 
      complex. Band 3 (K1/2 = 70 nM) or the membrane domain of band 3 (K1/2 = 100 nM) 
      bound saturably to immobilized CAII in a solid phase binding assay. The 
      interaction with CAII was specifically blocked by an antibody to the Ct of band 
      3. Affinity blotting showed that a glutathione S-transferase (GST)-fusion protein 
      (GST-Ct) containing the last 33 residues of human band 3 bound to CAII. The solid 
      phase binding assay showed that binding of GST-Ct to immobilized CAII was 
      saturable (K1/2 = 20 nM). The binding rate was slow (t1/2 = 12 h) at 
      physiological ionic strength and pH but was enhanced at low ionic strength or 
      acidic pH. Intact band 3 (Ki = 15 nM), the membrane domain of band 3 (Ki = 100 
      nM), or antibodies to the Ct of band 3 were able to block GST-Ct binding to CAII, 
      confirming the specificity of the interaction. Affinity chromatography showed 
      that CAII bound to immobilized GST-Ct with a 1:1 stoichiometry. This work 
      indicates that CAII, the bicarbonate supplier, is directly coupled to band 3, the 
      chloride/bicarbonate exchanger in red blood cells.
FAU - Vince, J W
AU  - Vince JW
AD  - Medical Research Council Group in Membrane Biology, Departments of Medicine and 
      Biochemistry, University of Toronto, Toronto M5S 1A8, Canada.
FAU - Reithmeier, R A
AU  - Reithmeier RA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Anion Exchange Protein 1, Erythrocyte)
RN  - 0 (Bicarbonates)
RN  - 0 (Carbonic Anhydrase Inhibitors)
RN  - 0 (Chlorides)
RN  - 0 (Enzymes, Immobilized)
RN  - 0 (Peptide Fragments)
RN  - 0 (Recombinant Fusion Proteins)
RN  - EC 4.2.1.1 (Carbonic Anhydrases)
RN  - O3FX965V0I (Acetazolamide)
SB  - IM
MH  - Acetazolamide/pharmacology
MH  - Anion Exchange Protein 1, Erythrocyte/isolation & purification/*metabolism
MH  - Bicarbonates/metabolism
MH  - Binding Sites
MH  - Carbonic Anhydrase Inhibitors/pharmacology
MH  - Carbonic Anhydrases/drug effects/isolation & purification/*metabolism
MH  - Chlorides/metabolism
MH  - Chromatography, Affinity
MH  - Enzymes, Immobilized
MH  - Erythrocyte Membrane/chemistry
MH  - Humans
MH  - Peptide Fragments/metabolism
MH  - Protein Binding
MH  - Recombinant Fusion Proteins/metabolism
EDAT- 1998/10/17 00:00
MHDA- 1998/10/17 00:01
CRDT- 1998/10/17 00:00
PHST- 1998/10/17 00:00 [pubmed]
PHST- 1998/10/17 00:01 [medline]
PHST- 1998/10/17 00:00 [entrez]
AID - S0021-9258(19)59614-4 [pii]
AID - 10.1074/jbc.273.43.28430 [doi]
PST - ppublish
SO  - J Biol Chem. 1998 Oct 23;273(43):28430-7. doi: 10.1074/jbc.273.43.28430.