Acedo-Espinoza E, Lagarda-Diaz I, Cabrera R, Guzman-Partida AM, Maldonado-Arce A, Ortega-Nieblas MM, Chan-Chan L, Vázquez-Moreno L. Insights into the Structural Features, Conformational Stability and Functional Activity of the Olneya tesota PF2 Lectin.
Protein Pept Lett 2021;
28:403-413. [PMID:
32798370 DOI:
10.2174/0929866527666200813204303]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND
The O. tesota lectin PF2 is a tetrameric protein with subunits of 33 kDa that recognizes only complex carbohydrates, resistant to proteolytic enzymes and has insecticidal activity against Phaseolus beans pest.
OBJECTIVE
To explore PF2 lectin features at different protein structural levels and to evaluate the effect of temperature and pH on its functionality and conformational stability.
METHODS
PF2 lectin was purified by affinity chromatography. Its primary structure was resolved by mass spectrometry and analyzed by bioinformatic tools, including its tertiary structure homology modeling. The effect of temperature and pH on its conformational traits and stability was addressed by dynamic light scattering, circular dichroism, and intrinsic fluorescence. The hemagglutinating activity was evaluated using a suspension of peripheral blood erythrocytes.
RESULTS
The proposed PF2 folding comprises a high content of beta sheets. At pH 7 and 25°C, the hydrodynamic diameter (Dh) was found to be 12.3 nm which corresponds to the oligomeric native state of PF2 lectin. Dh increased under the other evaluated pH and temperature conditions, suggesting protein aggregation. At basic pH, PF2 exhibited low conformational stability. The native PF2 (pH 7) retained its full hemagglutinating activity up to 45°C and exhibited one transition state with a melting temperature of 76.8°C.
CONCLUSION
PF2 showed distinctive characteristics found in legume lectins. The pH influences the functionality and conformational stability of the protein. PF2 lectin displayed a relatively narrow thermostability to the loss of secondary structure and hemagglutinating activity.
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