Combining genetically engineered oxidase with hydrogen bonded organic framework (HOF) for highly efficient biocomposites.

04 October 2021, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Hydrogen bonded organic frameworks (HOFs) with enzymes incorporated during their bottom-up synthesis represent functional biocomposites with promising applications in catalysis and sensing. High enzyme loading while preserving high specific activity is fundamental for development, but to combine these biospecific features with a porous carrier is an unmet challenge. Here, we explored synthetic incorporation of D-amino acid oxidase (DAAO) with metal-free tetraamidine/tetracarboxylate-based BioHOF-1. Comparison of different DAAO forms in BioHOF-1 incorporation revealed that N-terminal enzyme fusion with the positively charged module Zbasic2 (Z-DAAO) promotes the loading (2.5-fold; ~500 mg g-1) and strongly boosts the activity (6.5-fold). To benchmark the HOF composite with metal-organic framework (MOF) composites, Z-DAAO was immobilized into the zeolitic imidazolate framework-8 (ZIF-8), the relatively more hydrophilic analogue metal azolate framework-7 (MAF-7). While sensitivity to the framework environment limited the activity of DAAO@MAF-7 (3.2 U mg-1) and DAAO@ZIF-8 (≤ 0.5 U mg-1), the activity of DAAO@BioHOF-1 was comparable (~45%) to that of soluble DAAO (50.1 U mg-1) and independent of the enzyme loading (100 – 500 mg g-1). The DAAO@BioHOF-1 composites showed superior activity with respect to every reported carrier for the same enzyme and excellent stability during solid catalyst recycling. Collectively, our results show that the fusion of the enzyme with a positively charged protein module enables the synthesis of highly active HOF biocomposites suggesting the use of genetic engineering for the preparation of biohybrid systems with unprecedented properties.


d-amino acid oxidase
hydrogen-bonded organic frameworks
metal-organic frameworks
porous carrier


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.