Human Milk Lactoferrin Hydrolyzes Ribonucleoside 5′-Triphosphates.

Babina, S. E.; Semenov, D. V.; Buneva, V. N.; Nevinsky, G. A.

Lactoferrin (LF), one of the most important and polyfunctional factors of nonspecific cell defense against bacteria, viruses, and cancer diseases, is the main iron-transferring protein of human biological fluids, blood, and milk. Electrophoretically homogeneous preparations of LF from human milk were obtained and studied. Using chromatography on Blue Sepharose, LF preparations were separated into several subfractions differing in their affinity for the sorbent, two of which exhibited nucleoside 5-triphosphate-hydrolyzing activity. Using different methods, including in-gel ATPase activity assay, it was demonstrated that hydrolysis of ATP and other nucleotides is an intrinsic property of LF and that LF is the major ATPase of human milk. It is shown that the ATP-hydrolyzing center is located at the C-terminal domain of the LF molecule and that interaction between ATP and this center increases the oligonucleotide-hydrolyzing activity of the DNA-binding domain of this protein.

LACTOFERRIN; IRON proteins; BREAST milk; HYDROLYSIS; ALLOSTERIC proteins; DNA

Molecular Biology, 2005, Vol 39, Issue 3, p452

0026-8933

Academic Journal

10.1007/s11008-005-0061-5