Structural and Aggregation Features of a Human kappa-Casein Fragment with Antitumor and Cell-Penetrating Properties

Structural and Aggregation Features of a Human kappa-Casein Fragment with Antitumor and Cell-Penetrating Properties Full article

Journal

Molecules
, E-ISSN: 1420-3049

Output data

Year: 2019, Volume: 24, Number: 16, Article number : 2919, Pages count : DOI: 10.3390/molecules24162919

Tags

intrinsically disordered protein; dimerization; casein micelle; disulfide bond; beta-mercaptoethanol adduct

Authors

Chinak Olga A. ¹ , Shernyukov Andrey V. ^2,3 , Ovcherenko Sergey S. ^2,3 , Sviridov Evgeniy A. ^2,3 , Golyshev Victor M. ¹ , Fomin Alexander S. ¹ , Pyshnaya Inna A. ¹ , Kuligina Elena V. ¹ , Richter Vladimir A. ¹ , Bagryanskaya Elena G. ^2,3

Affiliations

1	(Данные Web of science) RAS, SB, Inst Chem Biol & Fundamental Med, Novosibirsk 630090, Russia
2	(Данные Web of science) RAS, SB, NN Vorozhtsov Novosibirsk Inst Organ Chem, Novosibirsk 630090, Russia
3	(Данные Web of science) Novosibirsk State Univ, Dept Nat Sci, 1 Pirogova Str, Novosibirsk 630090, Russia

Intrinsically disordered proteins play a central role in dynamic regulatory and assembly processes in the cell. Recently, a human kappa-casein proteolytic fragment called lactaptin (8.6 kDa) was found to induce apoptosis of human breast adenocarcinoma MCF-7 and MDA-MB-231 cells with no cytotoxic activity toward normal cells. Earlier, we had designed some recombinant analogs of lactaptin and compared their biological activity. Among these analogs, RL2 has the highest antitumor activity, but the amino acid residues and secondary structures that are responsible for RL2 ' s activity remain unclear. To elucidate the structure-activity relations of RL2, we studied the structural and aggregation features of this fairly large intrinsically disordered fragment of human milk kappa-casein by a combination of physicochemical methods: NMR, paramagnetic relaxation enhancement (PRE), Electron Paramagnetic Resonance (EPR), circular dichroism, dynamic light scattering, atomic force microscopy, and a cytotoxic activity assay. It was found that in solution, RL2 exists as stand-alone monomeric particles and large aggregates. Whereas the disulfide-bonded homodimer turned out to be more prone to assembly into large aggregates, the monomer predominantly forms single particles. NMR relaxation analysis of spin-labeled RL2 showed that the RL2 N-terminal region, which is essential not only for multimerization of the peptide but also for its proapoptotic action on cancer cells, is more ordered than its C-terminal counterpart and contains a site with a propensity for alpha-helical secondary structure.

Chinak O.A. , Shernyukov A.V. , Ovcherenko S.S. , Sviridov E.A. , Golyshev V.M. , Fomin A.S. , Pyshnaya I.A. , Kuligina E.V. , Richter V.A. , Bagryanskaya E.G.
Structural and Aggregation Features of a Human kappa-Casein Fragment with Antitumor and Cell-Penetrating Properties

Molecules. 2019. V.24. N16. 2919 . DOI: 10.3390/molecules24162919 WOS Scopus РИНЦ

Full text from publisher

Published online:

Aug 12, 2019

Web of science	WOS:000482998900124
Scopus	2-s2.0-85070725238
Elibrary	41634850
OpenAlex	W2967949689