title: Studies on human alpha uterine protein
Creators: name: Paterson, Wendy Forsyth
Publisher: name: University of Glasgow
Year: 1981
Subjects: subject: Molecular biology, obstetrics.

description: The aim of this research was to further the existing information on the human protein known as alpha uterine protein (AUP). Several independent lines of research were pursued and the following results were reported; 1. AUP from two of the major sources known, namely uterine decidua and amniotic fluid, was found to be immunologically- and electrophoretically-identical. This confirms a previous report of identity between AUP from these two sources. In addition, the molecular weight of amniotic fluid AUP was estimated by gel filtration to be approximately 53,700 daltons, which is similar to that previously estimated for decidual AUP by the same method. 2. An unusual peak morphology of AUP on AAGE was observed and investigated. The area enclosed by the AUP precipitin peaks was more deeply-staining than the surrounding gel, resulting in a "filled-in" appearance. This was found to be a feature of antibody/antigen specificity in that it was observed with antisera raised against AUP of decidual origin but not with antisera raised against amniotic fluid AUP, The exact nature of this effect remains uncertain. However, it may indicate incomplete antigenic identity between AUP from amniotic fluid and decidua, thereby contradicting the existing evidence of identity between AUP from these two sources, described in 1. 3. A component which may be structurally-related to AUP was detected in term cord serum. This was found to be of fetal rather than maternal origin. However, there was no evidence of immunological cross-reactivity between this "AUP-like" component in TCS and AUP. 4. To date, AUP has been detected in endometrium, myometrium, early gestation decidua, amnion, chorion and amniotic fluid. In this study, several other sources of AUP were discovered, namely early gestation (8-13 weeks) and term placenta, term decidua and mid-gestation fetal gut. Placental AUP was found to be electrophoretically- and immunologically-identical to that present in amniotic fluid and decidua, 5. The levels of AUP in early gestation (8-13 weeks) and term decidual and placental tissue were measured by one-dimensional AACE. Contrary to existing data on amniotic fluid AUP levels, no correlation between gestational age and concentration was found in either decidua or placenta. Similar levels of AUP were detected in both these tissues early in gestation, although the concentration in decidua was slightly higher than that in placenta at each stage of gestation. An overall decrease in AUP concentration towards term was observed in the decidua and placenta. However, the decline in concentration was much greater in placental tissue and only trace amounts of AUP were detectable at term, 6. An attempt to purify AUP from amniotic fluid by the three-step method of antibody affinity chromatography, ion exchange chromatography and gel filtration previously used to purify AUP from 11 week gestation decidua was unsuccessful. However, a two-step procedure involving ion exchange chromatography and Goncanavalin-A Sepharose chromatography gave better results. The resultant partially-purified material was enriched with AUP by approximately 21-fold and the concentration of the major contaminant protein, serum albumin, was reduced to about 1/12 of the initial level. However, no further purification was performed due to the relatively low yield of AUP obtained from the Con-A Sepharose chromatography step. The partially-purified AUP was radioiodinated with 125I and immune precipitates were analysed by SDS-polyacrylamide gel electrophoresis under denaturing conditions. Three components of molecular weights 48000, 16000 and 9000, respectively, were observed. This may indicate that amniotic fluid AUP is structurally different from that present in decidual tissue. However this observation awaits further confirmation. (Abstract shortened by ProQuest.).