Glucose oxidase streptavidin

Perhaps the most common conjugates of avidin or streptavidin involve attaching enzyme molecules for use in ELISA systems. As in the case of antibody-enzyme conjugation schemes (Chapter 10), by far the most commonly used enzymes for this purpose are horseradish peroxidase and alkaline phosphatase. Other enzymes such as (3-galactosidase and glucose oxidase are used less often, especially with regard to assay tests for clinically important analytes (Chapter 16). 

If p-galactosidasc is used to conjugate with an SMCC-activated avidin or streptavidin, then there is no need to thiolate the enzyme, since it contains sulfhydryls in its native state (Sivakoff and Janes, 1988 Fujiwara et al., 1988). For conjugations using horseradish peroxidase, alkaline phosphatase, or glucose oxidase, however, thiolation is necessary to add the requisite sulfhydryls. 

M. Snejdarkova, M. Rehak and M. Otto, Design of a glucose minisensor based on streptavidin glucose-oxidase complex coupling with self-assembled biotinylated phospholipid membrane on solid support, Anal. Chem., 65 (1993) 665-668. 

Glucose determination Glucose oxidase -h horseradish peroxidase Both enzymes co-immobilized via biotin-streptavidin on capillary wall Fluorescence (Resorufin)... 

Biotin-avidin D and biotin-streptavidin immobilization inside PDMS Glucose oxidase and horseradish peroxidase (i) 6-D-gluconolactone and hydrogen peroxide (ii) resorufin [173]... 

As with DNA above, a variety of proteins were immobilized non-covalently not only outside but also inside the CNT [138,150). Tsang et al. reported the first evidence for immobilization of small proteins inside MWNT by HRTEM [164-167], before DNA immobilization on the surface of MWNT as mentioned above [133,134]. After the innovative work by Sadler et aL, the cir-ciunference of CNTs was non-covalently functionalized with proteins directly or indirectly. MWNTs, prepared by arc discharge, were shown to be almost completely covered by streptavidin in helical arrangement [ 168]. SWNTs also adsorbed proteins and enzymes such as cytochrome c, ferritin, glucose oxidase and anti-fullerene IgG monoclonal antibody [169,170]. Indirect non-covalent functionaUzations of SWNTs with streptavidine and metallothionein were attained through triton-X 100-PEG-biotin and butylpyrene linkers, respectively [171,172]. 

---