Tetracyclines (TCs) Hapten Design and Synthesis
In reality, small chemical compounds of 700-1500 Da are not appropriate immunogens. But, when attached to macromolecules, they usually become great immunogenic agents. These small molecules are referred to as a hapten and macromolecules conferring hapten immunogenic are referred to as a carrier. The hapten can be thought of as an exogenous epitope linked to the carrier.
Tetracyclines (TCs) are broad-spectrum antibiotics discovered in the 1940s. They exhibit activity against a broad range of microorganisms (e.g. Gram-negative and Gram-positive bacteria, mycoplasmas, chlamydiae, and rickettsiae) and have extensively used to treat infectious diseases in both humans and animals. Specialized in the development of anti-hapten antibodies, Creative Biolabs offers a series of custom services for TC hapten design and synthesis, and helps clients to develop high-affinity small molecule antibodies against different targets.
Introduction to TCs
TC is a class of polyketide antibiotics derived from the Streptomyces genus of Actinobacteria. Naturally occurring drugs in this class include tetracycline, chlortetracycline, oxytetracycline, and demeclocycline. Semi-synthetic tetracyclines are methacycline, lymecycline, minocycline, doxycycline, and rolitetracycline. There’s one glycylcycline subclass drug, named after tigecycline. Lastly, a class of newer tetracyclines comprises ervacycline, sarecycline, and omadacycline. The basic structure of the TC molecule consists of a linear fused tetracyclic nucleus (A, B, C, D rings) to which many functional groups are attached. It’s applied in the treatment and management of a variety of bacterial infections by binding reversible to 30S ribosomal subunits of bacteria and preventing incoming tRNAs from binding to the ribosome. The simplest TC to reveal sensible antibacterial activity is 6-deoxy-6-demethyltetracycline and such structure may be the minimum pharmacophore.
Fig.1 Chemical structure of tetracycline.
Rational Hapten Design Services at Creative Biolabs
The most frequently used methods for analyzing TCs are microbiological and instrumental approaches. Microbiological techniques are generally complex, time-consuming, and lack specificity, whereas instrumental techniques require expensive facilities, large quantities of organic solvents, and complicated sample clean-up procedures. Antibody-based analytical methods render a rapid, sensitive, and cost-effective alternative if suitable antibodies are available. At Creative Biolabs, we are experts in developing antibodies for small molecular antigens and have established multiple design & synthesis strategies to produce optimized TC haptens, though only a few reports regarding the preparation of antibodies for TCs.
- Our Advanced Platforms with Manifold Strategies
- Hapten Design
- Hapten Modification
- Carrier Selection
To prepare antibodies against small-molecule compounds, the molecule structure of haptens should have a certain degree of complexity, such as holding benzene ring, heterocyclic group, and so like. Otherwise, the hapten would be difficult to immunize antibodies or produce antibodies with very low titers. TCs containing benzene ring satisfy this first requirement, which improves the rate of a successful production of antibodies according to related studies.
Numerous choices of modification sites on the hapten molecule can be concerned. When customers choose different modification sites to synthesize TC hapten derivatives, artificial antigens with different steric structures lead to generating antibodies with different affinity and specificity.
In the hapten-carrier conjugates, the carrier can increase the molecular weight of the antigen and transport the hapten, as well as induce the immune response of immunized animals to specifically recognizing haptens on the surface of the carrier. Here, we’d like to provide various carriers (commonly proteins) for artificial antigens, including bovine serum albumin (BSA), rabbit serum albumin (RSA), human serum albumin (HSA), thyroglobulin, fibrinogen, and immunoglobulin fragments. We also provide a chemical coupling method or immunological labeling method to accomplish the hapten derivative coupling with the carrier.
Our Rational Design and Synthesis Services
A synthesis way of haptens has described for TCs (tetracycline, chlortetracycline, and oxytetracycline) based on the formation of their carboxamido and diazo derivatives that maintain the tetracyclic nucleus and own an aliphatic or aromatic spacer arm, in order to exert a degree of heterology in the chemical structure. The haptens can be used to raise polyclonal antibodies successfully and a reliable indirect competitive enzyme-linked immunosorbent assay (ELISA) for TC is set up. The optimized ELISA demonstrates cross-reactivity to chlortetracycline (10%), methacycline (14%), oxytetracycline (30%), and rolitetracycline (91%).
The reactions undergo by TCs are difficult, indicated by the complex functionality and the sensitivity of this molecule to mild reaction conditions (e.g. pH and temperature). As well, their stability is very poor and form reversible epimers when facing strong acidic and alkaline conditions. For all these reasons, the synthesis and purification of TC haptens are intractabilities. At present, our teams aim to develop an easy synthetic pathway to synthesize haptens maintaining the original TC structure and devote to working on their further use to produce sensitive polyclonal/monoclonal antibodies. Additionally, we also build other proven design platforms including but not limited to:
- End-to-end solutions for hapten design services against many different challenging targets
- Multiple strategies to design and synthesize haptens to TCs, and assisting in subsequent antibody preparation
- There is a diversity of inexpensive carriers, BSA, RSA, HSA, with stable physicochemical properties for easy availability
- Follow-up services by experienced technical supports to create a better customer experience
To date, TCs have been one of the cheapest classes of antibiotics throughout the world, making them attractive in several countries with limited health care budgets. There is a need to develop acceptable, rapid, and cost-effective assays for TCs determination. Anti-hapten antibodies enable the detection of small molecules using simple and robust immunoassay-based methods, such as ELISA. As a top-ranking supplier in the antibody market, Creative Biolabs provides a range of advanced strategies for TC hapten design and synthesis, and performs custom development of anti-hapten polyclonal/monoclonal antibodies against these small molecules. If you’re interested in our services, please don’t hesitate to contact us.