Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sensitive immunoassays are essential for establishing the efficacy of recombinant vaccines to hepatitis B virus (HBV). These experimental vaccines include the PreS2 and S domains of the HBV envelope protein. To facilitate measurement of antibody against HBV PreS2, we employed the immuno-ligand assay with silicon sensor-based detection. Labeling of immune reagents with the haptens biotin and fluorescein allows adaptation to the immunofiltration light addressable potentiometric sensor (LAPS) system. A biotinylated monoclonal anti-PreS2 antibody and anti-PreS2 in clinical serum samples competitively bind in liquid phase to a fluorescein labeled PreS2 + S antigen. Streptavidin mediates the immobilization on biotinylated nitrocellulose membranes. Fluorescein mediates binding of an anti-fluorescein urease conjugate to the immune complex. Urease serves as the signal-generating component which subsequently is measured in the LAPS reader. In comparison to a competitive RIA, the immuno-ligand assay demonstrated a four-fold improved sensitivity using a smaller sample volume. The higher sensitivity resulted in earlier detection of seroconversion during a clinical vaccine study.
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PMID:Detection of antibody to the PreS2 sequence of the hepatitis B virus envelope protein using an immuno-ligand assay with a silicon sensor detection system. 176 51

By immunizing ground-state peptides or proteins, we can produce super catalytic antibodies possessing serine protease-like characteristics. The unique feature of super catalytic antibodies is their ability to decompose a target molecule that is being killed. The authors have succeeded in preparing super catalytic antibodies that destroy (i) the HIV-1 envelope protein gp41, (ii) chemokine receptor CCR5 peptide, and (iii) Helicobacter pylori urease, etc. Some of them can degrade antigens at high catalytic reaction rates. Regarding their Km and kcat, super catalytic antibodies show intermediary values between that of enzymes (high Km and kcat) and that of antibodies (low Km and kcat [=0]). The catalytic function of an antibody mostly resides in its light chain. From mouse Vkappa germline analysis, it became clear that super catalytic antibodies are generated from some discrete germlines such as bb1, cr1, cs1, bl1, bj2 and bd2. In these Vkappa germlines, at least one catalytic triad composed of three amino acid residues, namely, Asp1, Ser27a and His93, is encoded. Namely, the antibody light chains (super catalytic antibodies) generated from the germlines are inherently able to enzymatically decompose antigens. Thus, such antibody light chains can be referred to as antigenase (antigen-decomposing enzyme) and may have arisen during the evolution of antibodies to acquire a higher ability than that of enzymes for developing a sophisticated self-defense system for survival.
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PMID:Super catalytic antibody and antigenase. 1623 7