Steroid Hormones Hapten Design and Synthesis
By judicious attachment of steroid hormone haptens to a protein carrier, it tactfully solves the problem of non-immunogenic or low-immunogenic of low-molecular-weight hapten compounds, successfully eliciting the formation of anti-hapten antibodies. These antibodies direct against steroid hormone haptens and are important both for assays of hormones and drugs in biological fluids or for therapeutic applications in tumor therapy. Based on the advance of chemical criteria, theoretical studies, and molecular modeling assisted hapten design, Creative Biolabs provides best-fit customized services for the design, modification, and synthesis of steroid hormone haptens and associated antibodies to meet customers’ demands.
Brief Introduction of Steroid Hormones
Steroid hormones are derivatives of cholesterol that are most prominently synthesized by the adrenal gland and gonads. The structure of steroid hormones is characterized by four-ring fatty hydrocarbons containing a cyclopentane polyhydric nucleus. The sterane core is typically composed of seventeen carbon atoms, bonded in four "fused" rings: three six-member cyclohexane rings (rings A, B, and C) and one five-member cyclopentane ring (the D ring, commonly used to design haptens to generate the class-specific antibodies).
Fig.1 Structure of steroid hormones.
Usually, steroid hormones can be grouped into five classes:
- Glucocorticoids - cortisol (the major representative in most mammals)
- Mineralocorticoids - such as aldosterone
- Androgens - such as testosterone
- Estrogens - such as estradiol and estrone
- Progestogens - such as progesterone
In mammals, the steroid hormones play a major role in regulating many critical physiological processes and behaviors, such as survival of stress, injury (and illness), metabolism, inflammation, salt and water balance, immune functions, and reproduction.
Steroid Hormone Hapten Design and Synthesis
To stimulate the animals to produce specific antibodies directly, the steroid hormone haptens must be modified to introduce an accessible functional group as well as a connecting arm and then combined with a macromolecular carrier. The haptens can be coupled with a carrier directly if there are any active groups in the hapten molecule, such as -COOH, -NH, -OH; if not, the haptens should be redesigned.
The design variables of steroid hormone haptens that should be considered are listed as follows:
- The linker site on the steroid molecule
- The chemical nature and length of the bridge connecting hapten and carrier
- The nature of the carrier chosen
- The number of steroid residues attached to each carrier molecule
Because antibodies are thought to recognize part of the hapten molecule with specific characteristics, the designed-haptens should possess similar physicochemical properties. It has been documented that the linker site bears importantly on the specificity of the antibodies generated. Commonly, a linker group should be allocated to the opposite position of the most distinct groups of the target molecule.
Usually, the modified hapten molecules must have an active group at the terminal of the linker, amongst, -COOH or -NH is the most popular one that can be introduced to the hapten by a phenol hydroxyl acylation or a keto oximation reaction.
Suitable carrier macromolecules are usually albumins, thyroglobulins, haemocyanins, and polylysine that affect the intensity of the immune response.
The designed immunogenic complex can be conjugated with more than one steroid residue (hapten) against the same carrier protein, resulting in polyclonal antibodies that can recognize more than one compound at a time.
Steroid Hormone Hapten Associated Services at Creative Biolabs
With excellent expertise and abundant experience in antigen design and antibody development, Creative Biolabs has accomplished several cases in designing & preparing haptens, and developing small molecule antibodies. Our featured services include but not limited to:
- Design and Synthesis of Class-specific Haptens (D ring) for Steroid Hormones
- Design and Synthesis of Compound-specific Haptens (A ring /B ring) for Steroid Hormones
By thoroughly analyzing the chemical structures of the most common estrogens - estrone (E1), estradiol-17β (E2), and estriol (E3), our scientists perfectly synthesized the estrogen-haptens by introducing carboxyl groups to E1, E2, and E3 via replacing the hydroxyl group at the site 3 with bromohexanoic acid. Using these immunogens, we have been succeeded in obtaining highly specific monoclonal antibodies.
Notably, hapten based antibodies may have a cross-reaction with other estrogen drugs due to their similar chemical structures. To solve this challenge, we choose the position 6 as the linker site to design haptens, thus generating antibodies discriminating between the three major estrogenic hormones. In addition, we found that antibodies to progesterone 6-, 7- or 11- conjugates recognize changes in the 17-sidechain more efficiently than antibodies to the corresponding 20-conjugate.
Fig.2 Design and synthesis of E2 hapten at Creative Biolabs.
Considering and assessing the nature, availability, and structure of steroid hormones, Creative Biolabs provides hapten design and synthesis services to generate immunogen, as well as to develop high quality and high specific antibodies (compound or class selective). If you are interested in our services, please feel free to contact us for more information.