Immunological properties of two related fragments from human and equine growth hormones.

The research explores the immunological properties of specific fragments of the human and horse growth hormones. It suggests that both fragments show similar reactivity with the anti-human growth hormone serum, but only a part of the human fragment is present in the corresponding horse growth hormone.

Research Overview

• The research involved the comparative study of the immunological characteristics of a synthetic human growth hormone fragment and a natural horse growth hormone fragment.
• The human growth hormone fragment comprises of the amino acids 73 through 128, while the horse growth hormone fragment is formed by amino acids 73 through 123.
• Rabbits were inoculated with the native human hormone or the fragments to obtain antisera, which were then used in various experiments.

Hemagglutination Experiments

• The study used hemagglutination experiments to examine the reactivity of the hormone fragments against the anti-human growth hormone serum.
• Both fragments were found to display the same reactivity towards the anti-human growth hormone serum.

Complement Fixation Curves

• Complement fixation curves were used to reveal that at least two populations of antibodies presumably originated against the sequence 73-128 of the human growth hormone.
• Of these antibody populations, only one of the corresponding antigenic areas was found in the homologous region of the horse growth hormone.

Conclusion

• The research partially explains the known cross-reactivity observed between both hormones, indicating it occurs due to the presence of a common antigenic area in the compared growth hormone fragments.