The enzyme creatine amidinohydrolase is a clinically important enzyme used in the determination of creatinine in blood and urine. Continuous use biosensors are becoming more important in the clinical setting; however, long-use creatinine biosensors have not been commercialized due to the complexity of the three-enzyme creatinine biosensor and the lack of stability of its components. This paper, the second in a series of three, describes the immobilization and stabilization of creatine amidinohydrolase. Creatine amidinohydrolase modified with poly(ethylene glycol) activated with isocyanate retains significant activity after modification. The enzyme was successfully immobilized into hydrophilic polyurethanes using a reactive prepolymer strategy. The immobilized enzyme retained significant activity over a 30 day period at 37 degrees C and was irreversibly immobilized into the polymer. Despite being stabilized in the polymer, the enzyme remained highly sensitive to silver ions which were released from the amperometric electrodes. Computational analysis of the structure of the protein using the Gaussian network model suggests that the silver ions bind tightly to a cysteine residue preventing normal enzyme dynamics and catalysis.
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http://dx.doi.org/10.1016/j.actbio.2004.11.007 | DOI Listing |
mLife
December 2024
State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology Shanghai Jiao Tong University Shanghai China.
ACS Appl Mater Interfaces
December 2024
Biosensor National Special Laboratory, Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang 310027, PR China.
Creatinine (CRE) is frequently measured in clinical practice due to its recognized significance as a pivotal biomarker across a spectrum of renal and cardiovascular disorders. However, the rapid and accurate detection of CRE for assessing kidney and muscle functions remains challenging. Here, we prepared the poly(3,4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hydrogel uniformly loaded with Prussian blue nanoparticles (PBNPs) via a one-step metal-assisted electrochemical modification method on the screen-printed electrode for ultrasensitive CRE detection.
View Article and Find Full Text PDFMikrochim Acta
August 2024
School of Public Health, Nantong University, Nantong, 226019, Jiangsu Province, People's Republic of China.
Screen-printed carbon electrodes (SPCE) functionalized with MXene-based three-dimensional nanomaterials are reported for rapid determination of creatinine. TiCT MXene with in situ reduced AuNPs (MXene@AuNP) were used as a coreactant accelerator for efficient immobilization of enzymes. Creatinine could be oxidized by chitosan-embedded creatinine amidohydrolase, creatine amidinohydrolase, or sarcosine oxidase to generate HO, which could be electrochemically detected enhanced by Prussian blue (PB).
View Article and Find Full Text PDFClin Chim Acta
March 2023
Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo, Spain. Electronic address:
An electrochemical biosensor for creatinine determination in a drop of whole human blood was developed and applied to the determination of creatinine in real clinical samples. It is based on the modification of a dual carbon working electrode with a combination of three enzymes: creatinine amidohydrolase (CNN), creatine amidinohydrolase (CRN) and sarcosine oxidase (SOX). Electrochemical transduction is performed using horseradish peroxidase (HRP) and potassium hexacyanoferrate(II) as mediator.
View Article and Find Full Text PDFJ Phys Chem B
March 2023
School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China.
Improving protein thermostability in mutagenesis-based enzyme engineering was often achieved by enhancing interresidue interactions via mutation to increase the enthalpy penalty of unfolding. However, this approach may trade off the functional activity due to the loss of structural flexibility of the biomolecule. Here, by performing X-ray crystallography, enzymatic kinetic experiments, neutron scattering, and thermodynamical measurements, we compared the structures, catalytic behaviors, dynamics, and thermostability between a wild-type creatinase and its four-point mutant.
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