Selectivity of a C-terminal peptide antiserum for different DNA-binding states of the vitamin D receptor

N. J. Koszewski, T. A. Reinhardt, M. C. Langub, H. H. Malluche, R. L. Horst

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


Antisera against peptides from the extreme N- and C-terminal regions of the VDR were evaluated. The N-terminal antiserum Ab192 functioned as a general-purpose antibody, being able to supershift the rhVDR in heterodimeric or homodimeric binding complexes in the EMSA, and detect both recombinant and native forms of the receptor on Western blots. The C-terminal antiserum, Ab195, also identified the receptor on Western blots, but in contrast, it displayed differential sensitivity to the conditions employed in the EMSA. In the presence of 1,25(OH)2D3, rhVDR, rhRXRα, and nonspecific DNA, Ab195 produced a weak supershift of the heterodimer complex in the EMSA. Significantly, omission of hormone from the binding buffer resulted in a complete shift of the bound complex with the antiserum. A complete supershift was also observed if only the nonspecific DNA was removed. Together these results indicate antiserum sensitivity to the ligand status in the rhVDR C- terminus as part of a DNA-bound heterodimer complex. Inclusion of 9-cis RA resulted in a modest increase in the amount of shifted product relative to 1,25(OH)2D3 alone. Finally, Ab195 completely supershifted the rhVDR homodimer binding complex under all tested conditions, including those analogous to where it was largely ineffective in shifting the heterodimer. Thus, Ab195 is sensitive to the ligand binding status of the VDR, discriminates heterodimer and homodimer binding interactions, and should provide an additional tool for exploring conformational changes induced in the receptor.

Original languageEnglish
Pages (from-to)388-396
Number of pages9
JournalArchives of Biochemistry and Biophysics
Issue number2
StatePublished - Jan 15 1998

Bibliographical note

Funding Information:
This study was supported, in part, by NIH Grant DK47883 and Dialysis Clinic Incorporated (N.J.K.). The authors thank Holli D. Gravatte and Derrel A. Hoy for their excellent technical assistance. This work is dedicated to the memory of Dr. Angelo C. Notides: scholar, mentor, friend (N.J.K.).


  • Antiserum
  • Vitamin D
  • Vitamin D receptor

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology


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