Antagonistic cooperativity between crystal growth modifiers.

Area of Science:

• Crystallization science
• Materials science
• Biophysics

Background:

• Crystallization from multicomponent environments is common in nature and industry.
• Laboratory studies have primarily focused on pure solute crystallization and single growth modifiers.
• Understanding crystallization modifiers is crucial for controlling material synthesis and biological processes.

Purpose of the Study:

• To investigate the molecular mechanisms of pairs of inhibitors blocking haematin crystallization.
• To explore the synergistic and antagonistic cooperativity between different crystallization modifiers.
• To develop a molecular viewpoint on crystallization modifier interactions for guiding material synthesis.

Main Methods:

• Utilized scanning probe microscopy (SPM) to observe crystal growth at the molecular level.
• Employed molecular modeling to simulate and understand inhibitor-crystal interactions.
• Examined pairs of inhibitors with distinct mechanisms: kink blocking and step pinning.

Main Results:

• Inhibitor pairs exhibited both synergistic and antagonistic cooperativity in blocking haematin crystallization.
• Cooperativity depended on the specific inhibitor combination and their applied concentrations.
• Kink blockers were found to reduce step edge line tension, facilitating crystal layer nucleation and propagation.

Conclusions:

• Antagonistic cooperativity between crystallization modifiers is not captured by current crystal growth models.
• The molecular understanding of modifier interactions provides guidance for pairing modifiers in material synthesis.
• These findings offer strategies to control crystallization in complex natural and engineered systems.