Abstract
Bovine lactoferrin (LF) was used to prepare complexes with oleic acid (OA) and linoleic acid (LnA), the anti- tumor activity of the lactoferrin-oleic acid complex (LF-OA) and lactoferrin-linoleic acid complex (LF-LnA) was measured on liver cancer, colon cancer and breast cancer cells using the methylene blue method. The structure changes of LF induced by binding of OA and LnA, including hydrophobic amino acids, hydrophobic regions, tertiary structure, secondary structure, was studied by intrinsic fluorescence, ANS-binding intrinsic fluorescence and circular dichroism spectrum, respectively. Both of LF-OA and LF-LnA exhibited profound anti-tumor activity on the three types of tumor cells. A significant red-shift of LF occurred after binding of OA and LnA, respectively. Meanwhile, the ANS-binding spectra of LF exhibited a blue-shift with an increasing fluorescence intensity. It can be indicated from the fluorescence spectra results that binding of OA and LA lead to the exposure of hydrophobic amino acids and hydrophobic regions. Furthermore, circular dichroism spectra suggested a partial loss of the tertiary structure, a decrease in the content of a-helix and ß-turn with the increase of ß-sheet and random coil structure. Here in this study, we successfully prepared the two anti- tumor LF-OA and LF-LnA complexes, which exhibited a profound prospect of cancer therapy.
