Biochemical characterization of a novel sphingomyelinase-like protein from the Rhipicephalus microplus tick

Autor(es)

Silva, Fernando A. A. ; Costa, Gabriel C. A. ; Parizi, Luis F. ; Vaz Junior, Itabajara da Silva ; Tanaka, Aparecida S.

• Tipo de documento: Artigo Científico
• Fonte: Experimental Parasitology; v. 254, p. 10-pg., 2023-09-13.

Resumo

Sphingomyelinase D is a toxin present in venomous spiders and bacteria and is associated with infection symptoms in patients affected by spider bites. It was observed that in Ixodes scapularis ticks, sphingomyelinaselike protein secreted in saliva can modulate the host immune response, affecting the transmission of flavivirus to the host via exosomes. In this work, a sphingomyelinase D-like protein (RmSMase) from R. microplus, a tick responsible for economic losses and a vector of pathogens for cattle, was investigated. The amino acid sequence revealed the lack of important residues for enzymatic activity, but the recombinant protein showed sphingomyelinase D activity. RmSMase shows Ca2+ and Mg2+ dependence in acidic pH, differing from IsSMase, which has Mg2+ dependence in neutral pH. Due to the difference between RmSMase and other SMases described, the data suggest that RmSMase belongs to SMase D class IIc. RmSMase mRNA transcription levels are upregulated during tick feeding, and the recombinant protein was recognized by host antibodies elicited after heavy tick infestation, indicating that RmSMase is present in tick saliva and may play a role in the tick feeding process. (AU)

• Processo FAPESP: 20/02433-5 - Construção de uma biblioteca de fragmentos de cDNA de enzimas proteolíticas (peptidases) e serpinas de R. microplus na superfície de fagos filamentosos
• Beneficiário: Gabriel Cerqueira Alves Costa
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 12/03657-8 - Inibidores e proteases de ectoparasitas: relação de estrutura-função e identificação do papel dessas moléculas na interação de vetores de doenças e seus agentes etiológicos
• Beneficiário: Aparecida Sadae Tanaka
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 19/03779-5 - Uso de phage display como ferramenta no diagnóstico e controle de doenças transmitidas por vetores hematófagos
• Beneficiário: Aparecida Sadae Tanaka
• Modalidade de apoio: Auxílio à Pesquisa - Temático