# CELLULAR & MOLECULAR BIOLOGY OF ALTERED BAND 3

> **NIH NIH R01** · UNIVERSITY OF ARIZONA · 1991 · $72,384

## Abstract

The purpose of the proposed study is to investigate hereditary defects in
band 3, the major anion transport protein. We have discovered two unique
defects in band 3. One of the defects, "slow migrating band3", is
characterized by a band 3 molecule that migrates in gels as though it
were Mr 98,500 instead of Mr approximately 95,000 as does normal band 3.
Thus, it behaves as though there were an addition of Mr approximately
3,500 to the band 3 molecule. The other defect is "fast-migrating band 3"
which migrates in gels at Mr=92,000, as though there were a deletion
approximately 2,000-3,000 rom the band 3 molecule. Cells from individuals
with the latter defect have a significantly shortened lifespan and behave
in many ways like old red blood cells.

The specific aims of this project are to (1) determine what functional
defects are associated with band 3 structural defects; (2) define the
structural defects in terms of band 3 domains and amino acid sequence;
(3) determine whether the structural changes in band 3 affect its
interaction with other membrane and cytoskeletal proteins and whether
cytoskeletal proteins are normal; (40 determine the mode of inheritance
of band 3 defects in kindreds; (5) characterize antibodies bound to red
cells with band 3 anomalies; and (6) identify other defects in band 3 in
the population.

Band 3 will be characterized by gel electrophoresis before and after
treatment with endoglycosidase F to remove carbohydrate groups. The
number of IgG molecules per cell will be a determined using a DIDS
binding assay. IgG binding studies will be performed. If there are
abnormal amounts of IgG on red cells, IgG will be eluted and its
specificity determined. Anion transport studies will be performed as a
test of band 3 function, and ankyrin binding studies will used to test
band 3 interaction with ankyrin. Band 3 proteins that are abnormal as
determined by these assays will be analyzed by one and two dimensional
peptide mapping and fast atom bombardment mass spectroscopy, and the
amino acid sequence of the abnormal segment will be determined.
Cytoskeletal proteins will be screened by gel electrophoresis and binding
assays to determine whether their interactions with each other are
normal. It is anticipated that these studies will provide insights into
the structure and function of normal band 3 as well as into the molecular
basis of some anemias.

## Key facts

- **NIH application ID:** 3120302
- **Project number:** 5R01AG008574-04
- **Recipient organization:** UNIVERSITY OF ARIZONA
- **SAM.gov UEI:** ED44Y3W6P7B9
- **Principal Investigator:** MARGUERITE M KAY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $72,384
- **Award type:** 5
- **Project period:** 1990-10-01 → 1993-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3120302

## Citation

> US National Institutes of Health, RePORTER application 3120302, CELLULAR & MOLECULAR BIOLOGY OF ALTERED BAND 3 (5R01AG008574-04). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3120302. Licensed CC0.

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