Adsorption-induced changes in ribonuclease A structure and enzymatic activity on solid surfaces.

Area of Science:

• Biochemistry
• Materials Science
• Drug Delivery

Background:

• Ribonuclease A (RNase A) is a stable enzyme explored for cancer chemotherapy.
• Clinical use is limited by reduced stability and activity when attached to biomaterials.

Purpose of the Study:

• To assess RNase A's structural stability and enzymatic activity after adsorption onto various surfaces.
• To understand how surface chemistry affects RNase A's performance for drug delivery.

Main Methods:

• Circular dichroism and mass spectrometry analyzed protein structure changes.
• In vitro assays measured enzymatic activity post-adsorption.
• Tested surfaces included fused silica glass, HDPE, and PMMA.

Main Results:

• Adsorption induced significant RNase A unfolding, varying by surface chemistry.
• Enzymatic activity decreased by approximately 60% after adsorption, regardless of material.
• Structural alterations, particularly at the catalytic site, were observed.

Conclusions:

• RNase A's native structure is substantially altered by adsorption onto diverse surfaces.
• Maintaining RNase A's native structure is crucial for preserving enzymatic activity in drug delivery systems.
• Future drug delivery designs should prioritize methods to retain RNase A's structural integrity for effective antitumor chemotherapy.