Local structural difference between human and bovine band 3 in the anion transport inhibitor-binding region.
We have examined molecular properties of inhibitor-complexed human and bovine band 3, an anion transport protein of erythrocyte membrane, in order to demonstrate the structural characteristics of the inhibitor binding region. Band 3 modified with DIDS (4,4'-diisothiocyano-2,2'-stilbenedisulfonate), a potent anion transport inhibitor, generated a positive circular dichroic band at a wavelength of 345 nm, corresponding to a DIDS chromophore. The dichroic spectra of human band 3-DIDS complex and its bovine counterpart differed markedly in their ellipticity. Under the conditions that H2DIDS (the dihydro-derivative of DIDS) cross-linked two chymotryptic fragments of human band 3, the reagent failed to cross-link the equivalent bovine fragments. The inhibitory effect of PLP (pyridoxal 5'-phosphate), a substrate and affinity label, on phosphate influx into red blood cells was more pronounced for human band 3 than for bovine band 3. The residue Lys-562 of human band 3 was found to be modified with PLP, while the corresponding residue of bovine band 3 was devoid of reactivity with PLP.
Moriyama
R
R
Department of Applied Biological Sciences, School of Agricultural Sciences, Nagoya University, Japan.
Tomida
M
M
Hoshino
F
F
Makino
S
S
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000031:analogs & derivatives* / Q000737:chemistry*; D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry* / Q000302:isolation & purification; D002417:Cattle; D002463:Cell Membrane Permeability / Q000187:drug effects; D002845:Chromatography; D002918:Chymotrypsin / Q000378:metabolism; D002942:Circular Dichroism; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D011732:Pyridoxal Phosphate / Q000737:chemistry* / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism
D001457:Anion Exchange Protein 1, Erythrocyte; D003432:Cross-Linking Reagents; D010446:Peptide Fragments; D011732:Pyridoxal Phosphate; C018564:dihydro-DIDS; D012697:Serine Endopeptidases; D002918:Chymotrypsin; C036813:lysyl endopeptidase; D008239:Lysine; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid