Induction of Antibodies to Particular Sites of the α7 Subunit of the Nicotinic Acetylcholine Receptor in Mice of Different Lines

D. O. Koroev^1 #, M. A. Titova¹, T. D. Volkova¹, M. B. Oboznaya¹, M. P. Filatova¹, E. N. Fufacheva¹, M. N. Zhmak¹, V. I. Tsetlin¹, N. V. Bobkova¹ and O. M. Vol’pina¹

^#Phone: (495) 336-57-77; e-mail: koroev@ibch.ru

¹Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997, Russia

Received: May 4, 2006;  in final form: May 10, 2006

Abstract.  Five synthetic fragments of the N-terminal domain of the α7 subunit of the human nicotinic acetylcholine receptor (α7 nAChR) that correspond to theoretically calculated B epitopes and T helper epitopes of the protein and contain from 16 to 29 amino acid residues were tested for the ability to stimulate the formation of antibodies in mice of three lines having H-2^d, H-2^b, and H-2^k haplotypes of the major histocompatibility complex. It was shown that, in the free (unconjugated) form, all the peptides stimulate the formation of antibodies at least in one mouse line. Most of the peptides induced the formation of antibodies in BALB/c mice (haplotype H-2^d); therefore, more detailed studies were carried out on these animals. The free peptides and/or their conjugates with keyhole limpet hemocyanin were demonstrated to be capable of stimulating the formation in BALB/c mice of antibodies that bind to the recombinant extracellular N-terminal domain of (α7 nAChRα). The epitope mapping of antipeptide antibodies carried out using truncated fragments helped reveal antipeptide antibodies to four regions of the α7 subunit: 1–23, 98–106, 159–168, and 173–188 (or 179–188).

Key words:  acethylcholine receptor, α7 subunit, synthetic peptides, antibodies, B epitopes

Russian Journal of Bioorganic Chemistry 2007, 33 (4): 410-414