Isolation and characterization of glycoprotein (CNP) isolated from Cocos nucifera L. nutshell and its immunomodulatory role on macrophage activation

Abstract

The crude protein from Cocos nucifera L. nutshell was isolated and fractionized by GFC, yielding two protein peaks, CNP-F1 and CNP-F2 having a molecular weight of 43 kDa and 46 kDa, respectively as confirmed by MALDI-TOF. MS/MS analysis followed by MASCOT search confirmed CNP-F1 was gibberellin-20-oxidase and CNP-F2 was serine/threonine kinase-11. CNP-F1 (2.5 µg/mL) and CNP-F2 (0.5 µg/mL) upregulated the pro-inflammatory cytokines (IL-12, IFN-γ) release significantly (p < 0.01) with the prompt nitrite generation in murine peritoneal macrophages. It was also noteworthy that CNP-F2 showed better efficacy in terms of macrophage activation than CNP-F1. After that, the 3D structure of CNP-F2 was designed and validated by the Ramachandran plot. Later, in silico study indicated that CNP-F2 could bind with TLRs and modulate their expressions. Hence, the CNP-F2 protein, a serine/threonine kinase-11, from C. nucifera L. nutshell can be considered as a TLR-activating potential immunomodulator to boost macrophage-mediated immune responses.

Keywords

• Cocos nucifera L.
• Nutshell protein
• Giberillin-20-oxidase
• Serine/threonine kinase
• Macrophage activation
• Immunomodulation