The effectiveness of the carrier protein in eliciting antigen-specific antibodies was investigated. The effect of the carrier protein was independent of the conjugation chemistry involved. Keyhole limpet hemocyanin (KLH), purified protein derivative (PPD), and ovalbumin (OVA) were used as carrier proteins in the immunization of mice. Three antigens were studied: LY170881 (a small drug molecule), 4-[1'-cyanobenz(f)isoindolyl]butyric acid (CBI-butyric acid), and a seven residue peptide GPGRGPG (KLE1). The serum antibody response to the antigen or antigen:BSA conjugate was superior in the case where the PPD:antigen conjugates were used as the immunogen when compared to KLH and OVA. The specificity of the antibodies to the respective antigens vs cross-reactivity with the carrier protein was investigated. PPD-coupled antigen immunized mice generated a higher percentage of antigen-specific hybridomas compared to the other carrier proteins. These findings confirmed PPD as the best carrier molecule for the production of both polyclonal and monoclonal antibodies.

Animals↗

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Use of monoclonal anti-enzyme antibodies for analytical purposes.

This review discusses the analytical applications of monoclonal antibodies specific for enzymes. One important, but not well-studied, application of these monoclonal antibodies is their use in immobilizing enzymes on solid supports. This method is based on binding the enzymes to an immobilized antibody through the antigen binding site of the antibody. Enzymes immobilized this way retain much of their activity. The utility of immobilized enzyme reactors prepared by immobilizing the enzymes through antibodies is demonstrated by using them in the determination of acetylcholine and choline in brain tissue extracts. Currently available methods for immobilizing antibodies and enzymes are reviewed. Other issues discussed in this review include the problems and advantages of immobilized enzyme reactors, especially when used in conjunction with HPLC. In addition, the applications of monoclonal antibodies for the detection and measurement of enzymes and their isoforms are summarized.

Acetylcholine↗

PubMedDate not supplied

Ruptured abdominal aortic aneurysm. Pathognomonic triad.

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Abdomen↗

PubMedDate not supplied

Catalytic antibodies for complex reactions: hapten design and the importance of screening for catalysis in the generation of catalytic antibodies for the NDA/CN reaction.

Success in generating catalytic antibodies as enzyme mimics lies in the strategic design of the transition-state analog (TSA) for the reaction of interest, and careful development of screening processes for the selection of antibodies that are catalysts. Typically, the choice of TSA structure is straightforward, and the criterion for selection in screening is often binding of the TSA to the antibody in a microtiter-plate assay. This article emphasizes the problems of TSA design in complex reactions and the importance of selecting antibodies on the basis of catalysis as well as binding to the TSA. The target reaction is the derivatization of primary amines with naphthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide ion. The desired outcome is selective catalysis of formation of the fluorescent derivative in preference to nonfluorescent side-products. In the study, TSA design was directed toward the reaction branch leading to the fluorescent product. Here, we describe a microtiter plate-based assay that is capable of detecting antibodies showing catalytic activity at an early stage. Of the antibodies selected, 36% showed no appreciable binding to any of the substrates tested, but did show catalytic activity in derivatizing one or more of the amino acids screened. In contrast, only two out of 77 clones that showed binding did not show catalysis. Thus, in this complex system, observation of binding is a good predictor of the presence of catalytic activity, and failure to observe binding is a poor predictor of the absence of catalytic activity.

Animals↗

PubMedDate not supplied

In vitro and in vivo evaluation in dogs of a miniaturized glucose sensor.

A miniaturized glucose sensor was developed, consisting of a platinum wire entirely coated with teflon, except for a 1 mm section near its extremity where glucose oxidase is immobilized. The in vitro sensitivity to glucose of the sensors was 2.3 +/- 0.4 nA/mM, mean +/- SEM (n = 23). These sensors were implanted in the subcutaneous tissue of normal beagles. Two consecutive glucose infusions (15-30 mg/kg/min) were performed. The current generated by the sensor was used for calculation of the sensitivity coefficient (SC) (nA/mM), and the background current in the absence of glucose (lo) (nA). These parameters were used for determination of the apparent subcutaneous glucose concentration. The in vivo sensitivity was less than the in vitro sensitivity (0.5 +/- 0.1 vs. 2.2 +/- 0.2; n = 12 comparisons; p less than 0.01). Stability of sensor function was demonstrated by the absence in variation of SC and lo, calculated from the different plateaus obtained during the glucose infusions. This study provides a simple method for evaluating in vivo the function of a miniaturized sensor implanted in subcutaneous tissue.

Animals↗