REDUCING ENZYME CONFORMATIONAL FLEXIBILITY BY MULTIPOINT COVALENT IMMOBILIZATION

A thermostable esterase was immobilised to glyoxyl-agarose under condi tions designed to generate ''limited-linkage'' and ''multi-point'' cov alent derivatives. The multi-point derivative was 830-fold more thermo stable than the Limited-linkage derivative and retained more activity in the presence of sodium chloride and organic solvents. Medium chain (C8) aliphatic p-nitrophenyl ester substrates, which inactivate the so luble enzyme, were shown to be more readily hydrolysed. Together these data support the contention that multi-point covalent immobilisation results in a more rigid, less conformationally flexible protein struct ure.