Design and Synthesis of Class-specific Haptens (D ring) for Steroid Hormones

Steroid hormone haptens conjugated with a carrier protein can solve the problem of non-immunogenic due to the low molecular weight of steroid hormones. Besides, they can induce a strong immune response, and in turn, obtain a large number of antibodies. To distinguish different steroid molecules with similar chemical structures, it is necessary to design class-specific haptens to develop broad-spectrum antibodies. As a specialist in antibody development, Creative Biolabs has abundant experience and successful cases in designing, preparing haptens, and developing class-specific hapten antibodies.

Background of Steroid Hormones Haptens and Antibodies

Steroid hormones, when used as haptens, do not elicit immune responses until and unless conjugated with an immunogenic carrier, such as bovine serum albumin (BSA), ovalbumin (OVA), keyhole hemocyanin (KLH), human serum albumin (HSA), and rabbit serum albumin (RSA). The anti-hapten antibodies thus generated have been proven to be useful in serology, drug delivery, diagnosis, and development of immunodiagnostic kits or biosensors. The production of hapten antibodies with the desired specificity largely depends on the hapten design (preserving the similar chemical structure, physicochemical properties and spatial conformation of target compound), selection of the appropriate carrier protein and the conjugation method.

Design Principles of Steroid Hormones Haptens

The basic structure of most steroid hormones has three rings of six carbon atoms (A, B, and C) and one ring of five (D), the cyclopentanoperhydrophenanthrene nucleus. In the design of antigenic conjugates (steroid hormone haptens), the active group used to link the carrier protein is a major consideration, usually including carboxyl, hydroxyl, and amino group. Because many steroids don’t have an appropriate active group, the design and introduction of an active group is a necessary part for hapten design & synthesis. Besides, there are several variables should be also considered:

• the linker site, which bears importantly on the specificity of the antibodies generated;
• chemical nature and conjugation ratio of the hapten and carrier molecules, which affect the intensity of the immune response;
• hapten-carrier conjugation protocol (the original hapten is usually modified by introduction of spacer arms so that it is better to be recognized);
• cross-reactivity of generated antibodies.

Design and Synthesis of Class-specific Haptens for Steroid Hormones

Different hapten spacer site that connected with carrier proteins has a profound influence on the specificity spectrum of the resultant antibody. Most of the steroid hormones share a nearly similar structure of A and B rings, while possessing crucial differences in ring D. Because of the stereo-hindrance effect, the developed antibodies are thought to best recognize the part of the hapten molecule that is most distant from the conjugate linkage, therefore, it is desirable that a linker carrier is allocated to the opposite position (ring D) of the most characteristic groups of the target molecule. Through this modification approach, the resultant antibody can distinguish different compounds with high specificity.

In some opposite cases, scientists need to develop broad-spectrum steroid antibodies with the ability to recognize a class of similar steroid hormones, namely class-specific antibodies. To address this demand, we choose the D-ring (crucial differences) as the modification site to design the hapten and produce the desirable antibodies that can recognize a similar structure (A and B rings) with broad-spectrum reaction. Based on this guideline, Creative Biolabs has successfully designed several class-specific haptens for steroid hormones, as well as developed high-quality and class-specific antibodies with broad-spectrum reaction.

What Can We Help You?

Specialized in the development of antibodies, Creative Biolabs offers custom services for hapten molecules design, modification, and synthesis, as well as anti-hapten antibody development.

Fig.2 Services at Creative Biolabs.

Anti-hapten antibodies play important roles in the field of human health, for diagnostic and theranostic applications, as well as food safety and environmental monitoring. If you are doing hapten-associated studies, please feel free to contact us for scientific support and technical services.