title: Resistance to degradation and cellular distribution are important features for the antitumor activity of gomesin.
abstract: Many reports have shown that antimicrobial peptides exhibit anticancer abilities. Gomesin (Gm) exhibits potent cytotoxic activity against cancer cells by a membrane pore formation induced after well-orchestrated intracellular mechanisms. In this report, the replacements of the Cys by Ser or Thr, and the use D-amino acids in the Gm structure were done to investigate the importance of the resistance to degradation of the molecule with its cytotoxicity. [Thr(2,6,11,15)]-Gm, and [Ser(2,6,11,15)]-Gm exhibits low cytotoxicity, and low resistance to degradation, and after 24 h are present in localized area near to the membrane. Conversely, the use of D-amino acids in the analogue [D-Thr(2,6,11,15)]-D-Gm confers resistance to degradation, increases its potency, and maintained this peptide spread in the cytosol similarly to what happens with Gm. Replacements of Cys by Thr and Gln by L- or D-Pro ([D-Thr(2,6,11,15), Pro(9)]-D-Gm, and [Thr(2,6,11,15), D-Pro(9)]-Gm), which induced a similar β-hairpin conformation, also increase their resistance to degradation, and cytotoxicity, but after 24 h they are not present spread in the cytosol, exhibiting lower cytotoxicity in comparison to Gm. Additionally, chloroquine, a lysosomal enzyme inhibitor potentiated the effect of the peptides. Furthermore, the binding and internalization of peptides was determined, but a direct correlation among these factors was not observed. However, cholesterol ablation, which increase fluidity of cellular membrane, also increase cytotoxicity and internalization of peptides. β-hairpin spatial conformation, and intracellular localization/target, and the capability of entry are important properties of gomesin cytotoxicity.
authors: Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors: Marcus V
authors: MV
authors: Buri
authors: Tatiana M
authors: TM
authors: Domingues
authors: Edgar J
authors: EJ
authors: Paredes-Gamero
authors: Rafael L
authors: RL
authors: Casaes-Rodrigues
authors: Elaine Guadelupe
authors: EG
authors: Rodrigues
authors: Antonio
authors: A
authors: Miranda
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology / Q000633:toxicity; D000970:Antineoplastic Agents / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology / Q000633:toxicity; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002738:Chloroquine / Q000494:pharmacology / Q000633:toxicity; D004705:Endocytosis; D008546:Melanoma, Experimental; D051379:Mice; D011485:Protein Binding; D021381:Protein Transport
chemical_list: D023181:Antimicrobial Cationic Peptides; D000970:Antineoplastic Agents; C415987:gomesin; D002738:Chloroquine