Enzyme accessibility and solid supports: which molecular weight enzymes can be used on solid supports? An investigation using confocal Raman microscopy.

The accessibility of various solid supports (TentaGel, PEGA 1900, and beaded controlled pore glasses (CPGs)) to a range of enzymes was investigated. The different beaded materials were loaded with the peptide 4-cyanobenzamide-Gly-Pro-Leu-Gly-Leu-Phe-Ala-Arg-OH and incubated with the enzymes MMP-12 (22 kDa), thermolysin (35 kDa), MMP-13 (42.5 kDa), clostridium collagenase (68 kDa), and NEP (90 kDa). The absence/presence of the cyano stretching frequency was measured by means of confocal Raman microscopy. It was found that none of the investigated enzymes could enter the polymer matrices of TentaGel. PEGA 1900 was compatible only with the two smallest enzymes, while beaded CPG was successful even with NEP (90 kDa), proving its superiority over other materials in terms of bio-compatibility.