In this study, the concept of autoinhibition, a mechanism of protein activity regulation, was applied to the design and engineering of a β-lactamase zymogen. Using this zymogen, a sensitive protease assay method was developed in which activation of the zymogen by proteases produces an amplified absorbance signal. The approach reported here can be adapted for engineering of zymogens as biologica...

A typical glucose sensor is a oxidase (GOx) enzyme-based due to its high sensitivity and selectivity. However, it has difficulty activating stabilizing the enzyme. To enhance stability of GOx-based sensors, chitosan added ZnS-doped Mn nanoparticles. Chitosan stabilizes particles can induce charge processes such as creation, transfer, separation at polymer interface nanoparticles' interface. Hen...

Based on the characterization of a PCR mutation of water-soluble glucose dehydrogenase possessing pyrroloquinoline quinone (PQQ), PQQGDH-B, Ser231Cys, we have constructed a series of Ser231 variants. The replacement of Ser231 to Cys, Met, Leu, Asp, Asn, His, or Lys resulted in an increase in thermal stability. Among these variants, Ser231Lys showed the highest level of thermal stability and als...

pH-sensitive field effect transistors (FET) were modified with organophosphate hydrolase (OPH) and used for direct detection of organophosphate compounds. OPH is the organophosphate degrading gene product isolated from Pseudomonas diminuta. OPH was selected as an alternative to acetylcholinesterase, which requires inhibition mode sensor operation, enzyme regeneration before reuse, long sample i...

Two-component signal transduction systems, where the phosphorylation state of a regulator protein is modulated by a sensor kinase, are common in bacteria and other microbes. In many of these systems, the sensor kinase is bifunctional catalyzing both, the phosphorylation and the dephosphorylation of the regulator protein in response to input signals. Previous studies have shown that systems with...