168158 20260127160850.0 doi 10.1021/bm500333v sideral 147686 ART-2014-147686 eng Velasco-Lozano, Susana (orcid)0000-0001-9478-6750 Carrier-Free Immobilization of Lipase from <i>Candida rugosa</i> with Polyethyleneimines by Carboxyl-Activated Cross-Linking 2014 Carrier-free immobilization of Candida rugosa lipase (CRL) and polymers containing primary amino groups were cross-linked using carbodiimide. To accomplish this, the free carboxyl groups of the enzyme were activated with carbodiimide-succinimide in organic medium, and then the activated proteins were cross-linked with different polyethyleneimines (PEIs). The effect of the cross-linker chain length, the amount of added bovine serum albumin (BSA), and carbodiimide concentration on the catalytic properties of resulting cross-linked enzyme aggregates (CLEAs) was investigated. The CLEAs’ size, shape, specific activity, activity recovery, thermostability and enantioselectivity significantly varied according to the preparation procedure. The highest thermostable CRL-CLEA preparation was obtained with 1.3 kDa polyethyleneimine as cross-linker, 10 mg of BSA and 28 mM of carbodiimide. This preparation is 1.3-fold more active and thermostable than CLEAs prepared by the traditional method of amino cross-linking with glutaraldehyde, and retains 60% of residual activity after 22 h at 50°C. Additionally, the CRL-CLEA preparation showed an enantioselectivity of 91% enantiomeric excess (ee). This immobilization procedure provides an alternative strategy for CLEA production, particularly for enzymes where the traditional method of cross-linking via lysine residues leads to enzyme inactivation. Access copy available to the general public Unrestricted info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 5.75 2014 BIOCHEMISTRY & MOLECULAR BIOLOGY 39 / 290 = 0.134 2014 Q1 T1 POLYMER SCIENCE 5 / 82 = 0.061 2014 Q1 T1 CHEMISTRY, ORGANIC 5 / 58 = 0.086 2014 Q1 T1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion López-Gallego, Fernando Vázquez-Duhalt, Rafael Mateos-Díaz, Juan C. Guisán, José M. Favela-Torres, Ernesto 15, 5 (2014), 1896-1903 Biomacromolecules BIOMACROMOLECULES 1525-7797 693387 http://zaguan.unizar.es/record/168158/files/texto_completo.pdf Postprint 1174917 http://zaguan.unizar.es/record/168158/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:168158 articulos driver 2026-01-27-15:01:33 ARTICLE