Homologous Hevea brasiliensis REF (Hevb1) and SRPP (Hevb3) present different auto-assembling.

Area of Science:

• Biochemistry
• Biophysics
• Materials Science

Background:

• Hevea brasiliensis latex coagulation involves proteins like HbREF and HbSRPP.
• Previous findings indicated HbREF possesses amyloid properties relevant to coagulation.
• The precise roles of these proteins in latex processing remain largely undefined.

Purpose of the Study:

• To investigate the aggregation, auto-assembly, and interaction mechanisms of HbREF and HbSRPP.
• To elucidate the functional implications of these protein behaviors in Hevea brasiliensis latex.
• To determine if HbREF and HbSRPP exhibit antimicrobial or membrane-interacting activities.

Main Methods:

• Biochemical analyses including PAGE, spectroscopy, and microscopy.
• Biophysical techniques such as Dynamic Light Scattering (DLS) and ellipsometry.
• Structural investigations using Transmission Electron Microscopy (TEM), ATR-FTIR, and PM-IRRAS.

Main Results:

• HbREF and HbSRPP are confirmed as non-glycoproteins.
• HbREF self-assembles into amyloid-rich β-sheet structures and large aggregates.
• HbSRPP forms stable, globular nanomultimers; it may inhibit HbREF amyloidogenesis.
• HbREF agglutinates yeast and erythrocytes by interacting with cell membranes.
• Neither protein demonstrated antimicrobial activity, but membrane interactions were evident.

Conclusions:

• Distinct auto-assembly properties of HbREF and HbSRPP suggest roles in latex coagulation.
• Protein-membrane interactions may contribute to latex colloidal stability.
• Protein-protein interactions likely drive rubber particle aggregation during coagulation.
• These findings offer insights into the molecular mechanisms of Hevea brasiliensis latex coagulation.