Abstract
Purified vitamin D-dependent rat intestinal (Mr 10,000) and rat renal (Mr 28,000) calcium-binding proteins (CaBPs) have been compared to vertebrate calmodulin, and the vitamin D-dependent CaBPs have been found to be distinct from calmodulin by biochemical and immunochemical criteria. Rat renal and rat intestinal CaBPs do not stimulate 3′,5′-cyclic nucleotide phosphodiesterase, do not compete with iodinated calmodulin for binding to phenothiazine-Sepharose conjugates, do not cross-react immunochemically, and do not contain Nε{lunate}-trimethyllysine. In addition, although calmodulin exhibits a characteristic calcium-dependent mobility shift on polyacrylamide gels in the presence of sodium dodecyl sulfate, a similar mobility shift is not observed for the vitamin D-dependent CaBPs. Immunocytochemically, calmodulin has a widespread localization in the kidney, whereas CaBP is present specifically in the distal tubules of the kidney. These localizations suggest a specialized role for CaBP in the kidney. Thus, although the vitamin D-dependent CaBPs and calmodulin are similar in that they are small, acidic, calcium-binding proteins, these two classes of proteins are biochemically and immunochemically distinct.
| Original language | English |
|---|---|
| Pages (from-to) | 38-47 |
| Number of pages | 10 |
| Journal | Archives of Biochemistry and Biophysics |
| Volume | 231 |
| Issue number | 1 |
| DOIs | |
| State | Published - May 15 1984 |
Bibliographical note
Funding Information:These studies were supported in part by National Science Foundation Grant PCM 8302912 (L.V.E.), National Science Foundation Grant PCM 8103421 (S.C.), and NIH Grants HD12335 (M.E.B.) and NS20270-01 (S.C.). S.C. is a recipient of a Research Career Development Award from the National Institute of Arthritis, Diabetes, Digestive, and Kidney Diseases (AM 01200-01).
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology