WPK5, a Novel Kunitz-Type Peptide from the LeechInhibiting Factor XIa, and Its Loop-Replaced Mutant to Improve Potency.
Research article published in Biomedicines (2021)
Abstract
Kunitz-type proteins or peptides have been found in many blood-sucking animals, but the identity of them in leeches remained elusive. In the present study, five Kunitz-type peptides named WPK1-WPK5 were identified from the leech Whitmania pigra. Recombinant WPK1-WPK5 were expressed in Pichia pastoris GS115, and their inhibitory activity against Factor XIa (FXIa) was tested. WPK5 showed inhibitory activity against FXIa with an IC50 value of 978.20 nM. To improve its potency, the loop replacement strategy was used. The loop 1 (TGPCRSNLER) and loop 2 (QYGGC) in WPK5 were replaced by loop 1 (TGPCRAMISR) and loop 2 (FYGGC) in PN2KPI, respectively, and the resulting peptide named WPK5-Mut showed an IC50 value of 8.34 nM to FXIa, which is about 100-fold the potency of FXIa compared to that of WPK5. WPK5-Mut was further evaluated for its extensive bioactivity in vitro and in vivo. It dose-dependently prolonged APTT on both murine plasma and human plasma, and potently inhibited FeCl3-induced carotid artery thrombosis in mice at a dose of 1.5 mg/kg. Additionally, WPK5-Mut did not show significant bleeding risk at a dose of 6 mg/kg. Together, these results showed that WPK5-Mut is a promising candidate for the development of an antithrombotic drug.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Kunitz-type proteins or peptides have been found in many blood-sucking animals, but the identity of them in leeches remained elusive. In the present study, five Kunitz-type peptides named WPK1-WPK5 were identified from the leech.
Por qué esto importa para la hirudoterapia
Este estudio identificó cinco péptidos de tipo Kunitz (WPK1-WPK5) de la sanguijuela Whitmania pigra, los expresó de forma recombinante y determinó que el WPK5 inhibía el Factor XIa de la coagulación (IC50 978.20 nM); una variante de ingeniería con reemplazo de bucle, WPK5-Mut, resultó ser aproximadamente 100 veces más potente (IC50 8.34 nM), prolongó los tiempos de coagulación en plasma murino y humano, inhibió la trombosis carotídea inducida por FeCl3 en ratones a 1.5 mg/kg y no mostró hemorragias significativas a 6 mg/kg. Este es uno de los aportes más directamente relevantes para la misión de la ASH: es evidencia concreta de que el secretoma de la sanguijuela medicinal produce péptidos anticoagulantes novedosos y fármacos potenciales, y que la ingeniería de proteínas puede optimizar una molécula natural de sanguijuela para convertirla en un candidato a fármaco antitrombótico. El trabajo es preclínico (ensayos in vitro y modelos de roedores con un mutante de ingeniería), no un RCT, por lo que respalda la lógica del descubrimiento de fármacos derivados de sanguijuelas, pero no aporta información sobre la hirudoterapia clínica ni sobre la eficacia y seguridad en humanos.
Citación
WPK5, a Novel Kunitz-Type Peptide from the LeechInhibiting Factor XIa, and Its Loop-Replaced Mutant to Improve Potency.
Zheng YZ et al. · Biomedicines, 2021
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: June 18, 2026