Water structuring centers of mammalian cell surfaces

Area of Science:

• Cell Biology
• Biophysics

Background:

• Mammalian cells possess surface structures with unknown functions.
• Ice nucleation is a critical process in various biological systems.

Purpose of the Study:

• To characterize novel ice-nucleating centers (I-centers) on cultured mammalian cells.
• To investigate the properties and potential function of these I-centers.

Main Methods:

• Development of a two-dimensional crystallization assay to detect I-centers.
• Analysis of I-center expression, sensitivity to various treatments (dehydration, enzymes, proteases), and detachment from cells.

Main Results:

• Cultured mammalian cells express I-centers on their surface, detectable via ice nucleation.
• I-center expression is time-dependent (approx. 24h) and independent of cell density and metabolic energy.
• I-centers are sensitive to dehydration, hyaluronidase, and phospholipase C, but resistant to many proteases.
• Proteases like pronase can detach I-centers without compromising their ice-nucleating ability.
• I-centers are specific products of live cells, organized in detachable structures.

Conclusions:

• I-centers are cell-surface components with ice-nucleating properties.
• Their sensitivity to specific enzymes suggests a complex biochemical composition.
• The ability to influence water structure is proposed as a potential function of I-centers.