RESUMEN
Amblyomin-X is a Kunitz-type FXa inhibitor identified through the transcriptome analysis of the salivary gland from Amblyomma sculptum tick. This protein consists of two domains of equivalent size, triggers apoptosis in different tumor cell lines, and promotes regression of tumor growth, and reduction of metastasis. To study the structural properties and functional roles of the N-terminal (N-ter) and C-terminal (C-ter) domains of Amblyomin-X, we synthesized them by solid-phase peptide synthesis, solved the X-Ray crystallographic structure of the N-ter domain, confirming its Kunitz-type signature, and studied their biological properties. We show here that the C-ter domain is responsible for the uptake of Amblyomin-X by tumor cells and highlight the ability of this domain to deliver intracellular cargo by the strong enhancement of the intracellular detection of molecules with low cellular-uptake efficiency (p15) after their coupling with the C-ter domain. In contrast, the N-ter Kunitz domain of Amblyomin-X is not capable of crossing through the cell membrane but is associated with tumor cell cytotoxicity when it is microinjected into the cells or fused to TAT cell-penetrating peptide. Additionally, we identify the minimum length C-terminal domain named F2C able to enter in the SK-MEL-28 cells and induces dynein chains gene expression modulation, a molecular motor that plays a role in the uptake and intracellular trafficking of Amblyomin-X.
RESUMEN
Bradykinin-potentiating peptides (BPPs) or proline-rich oligopeptides (PROs) isolated from the venom glands of Bothrops jararaca (Bj) were the first natural inhibitors of the angiotensin-converting enzyme (ACE) described. Bj-PRO-5a (Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/farmacología
, Bothrops
, Venenos de Crotálidos/farmacología
, Dominios Proteicos Ricos en Prolina/fisiología
, Receptor de Bradiquinina B2/fisiología
, Receptor Muscarínico M1/fisiología
, Vasodilatación/efectos de los fármacos
, Inhibidores de la Enzima Convertidora de Angiotensina/química
, Inhibidores de la Enzima Convertidora de Angiotensina/aislamiento & purificación
, Animales
, Células CHO
, Cricetinae
, Cricetulus
, Venenos de Crotálidos/química
, Venenos de Crotálidos/aislamiento & purificación
, Relación Dosis-Respuesta a Droga
, Células HEK293
, Humanos
, Masculino
, Ratones
, Ratones Endogámicos BALB C
, Vasodilatación/fisiología