# STRUCTURE AND FUNCTION OF PREGNANCY RECOGNITION HORMONE

> **NIH NIH R01** · UNIVERSITY OF FLORIDA · 1994 · $153,902

## Abstract

Maternal recognition of pregnancy in sheep is dependent upon secretion of
ovine trophoblast protein-1 (oTP-1) by the conceptus. Between days 13 and
21 of pregnancy, oTP-1 represents the major conceptus secretory product,
and it is responsible for inhibition of uterine prostaglandin F2alpha
secretion. The oTP-1-induced inhibition of pulsatile secretion of
prostaglandin F2alpha by the uterus allows for maintenance of the corpus
luteum with continued secretion of progesterone. Porcine and bovine
conceptuses have also been shown to produce similar antiluteolytic
agents, and a human equivalent has been postulated as well. oTP-1 has
recently been shown to share amino acid homology with alpha interferons.
Thus, oTP-1 is involved in the interaction between the conceptus and
maternal systems which results in appropriate endocrinological and
immunological responses in early pregnancy.

We propose to examine the structure/function basis for pregnancy
recognition and other biological effects of oTP-1 using the synthetic
peptide approach for both direct receptor competition and production of
monoclonal antibodies to oTP-1 and oTP-1 synthetic peptides. It is
planned that the objective be achieved through the following approach:
(1) perform competitive receptor binding and functional experiments
between synthetic peptides and oTP-1, and determine the ability of
appropriate peptides to bind to the oTP-1 receptors; particular emphasis
will be placed on the use of longer peptides (possible domains); (2)
modify peptides that are important in receptor competition by systematic
removal and/or substitution of amino acids in order to more precisely
identify sequences or regions of oTP-1 that are involved in functions:
(3) generate monoclonal antibodies to oTP-1 and determine their ability
to block function and/or binding of oTP-1 to membrane receptors; (4) map
the epitope specificity of these monoclonal antibodies using synthetic
peptides that correspond to regions of the oTP-1 molecule located on the
surface; (5) use synthetic peptides to produce site specific monoclonal
and polyclonal antibodies and determine their effect on functions and
receptor binding by oTP-1: (6) determine the steric relationship of
epitopes, (and thus various regions) of oTP-1 by competitive binding
between monclonal antibodies (and their Fab fragments) of defined epitope
specificities with oTP-1. The proposed studies are important because they
will provide information on the structural basis for pregnancy
recognition and the antiviral properties of oTP-1.

## Key facts

- **NIH application ID:** 2199819
- **Project number:** 5R01HD026006-05
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **SAM.gov UEI:** NNFQH1JAPEP3
- **Principal Investigator:** HOWARD M JOHNSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $153,902
- **Award type:** 5
- **Project period:** 1989-09-30 → 1994-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2199819

## Citation

> US National Institutes of Health, RePORTER application 2199819, STRUCTURE AND FUNCTION OF PREGNANCY RECOGNITION HORMONE (5R01HD026006-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2199819. Licensed CC0.

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