1992 Fiscal Year Final Research Report Summary
Molecular Mechanisms of Anion Transport System across the Biological Membranes
| Project/Area Number |
03670150
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Pathological medical chemistry
|
|---|
| Research Institution | Fukuoka University |
|---|
Principal Investigator |
HAMASAKI Naotake Fukuoka Univ.Medical School, Professor, 医学部, 教授 (00091265)
|
|---|
| Project Period (FY) |
1991 – 1992
|
| Keywords | Anion Transport / Band 3 Protein / Transport Active Center / Hemolytic Anemia / Primary Structure / Phosphoenolpyruvate Transport |
|---|
| Research Abstract |
A peptide containing 78 amino acids including the carboxyl-terminus of band 3 was affinity-labeled with pyridoxal phosphate, a substrate for anion transport, and was purified by a combination of gel permeation and reverse-phase high performance liquid chromatography. The 61st lysine residue from the carboxyl terminus was the affinity-labeled site which is Lys-851 in the deduced sequence of human erythroid band 3. The peptide also contained the acylation site of Cys-843 near Lys-851 and its surrounding sequence, F--I-IICLAVL. was completely conserved in the G2 protein of the Rift valley fever virus. It will be interesting to determine th functional role of acylation in anion transport.
Amino acid residues of lysine, arginine and glutamic acid in the band 3 molecule are known to be essential for anion transport activity. Using resealed ghosts and diethyl pyrocarbonate, we have shown that an intracellular histidine residue of band 3 also participates in anion transport. The functional histidine residue was protected from diethyl pyrocarbonate modification by binding of dinitrostilbene-2, 2'-disulfonic acid to band 3 and the reverse relationship was also true, suggesting that a portion of band 3 containing a histidine residue is moved relevantly during the anion transport process. His-819 in the deduced sequence is a candidate for the mobile histidine residue. The His-819 is predicted to be located at the beginning of the hydrophilic connector loop which is linked to the carboxyl-terminus peptide. We believe, therefore, that the portion of band 3 must be a significant part of the anion transport center.
|
