Interaction of Oligonucleotides with Barrier Fluid Proteins

P. P. Laktionov,^1,2 E. Yu. Rykova,¹ D. V. Krepkii,¹ A. V. Bryksin,¹ and V. V. Vlassov¹

¹Novosibirsk Institute of Bioorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, pr. Lavrent'eva 8, Novosibirsk, 630090 Russia; fax: (383-2) 35-16-65; E-mail: rykova@modul.bioch.nsk.su

²To whom correspondence should be addressed.

Submitted July 19, 1996; revision submitted February 14, 1997.

---

Affinity modification of proteins was used to study their interactions with oligonucleotides in barrier fluids. Several proteins of saliva and tears were shown to undergo affinity modification during incubation with an alkylating derivative of deoxyribooligonucleotides. In tears, such proteins were lactoferrin, immunoglobulin G, and lysozyme; in saliva, immunoglobulin A and lysozyme. The data showed that the affinity for oligonucleotides decreased in the order lactoferrin > lysozyme > immunoglobulin A > immunoglobulin G. The binding of reactive oligonucleotide derivatives with the proteins was competitively inhibited by polyanions, such as oligonucleotides of various nucleotide compositions, single-stranded and double-stranded DNA, heparin, and dextran sulfate. Interactions between oligonucleotides and proteins can strongly affect the metabolism of oligonucleotides and their ability to permeate biological barriers.

---

KEY WORDS: oligonucleotides, proteins of barrier fluids, lactoferrin, immunoglobulins, lysozyme.

---