IDENTIFICATION OF CYCLOPHILIN-A FROM HUMAN DECIDUAL AND PLACENTAL TISSUE IN THE FIRST TRIMESTER OF PREGNANCY

The protein patterns of tissue homogenates from human decidua and plac enta of first trimester pregnancies were investigated. Particular atte ntion was paid to the low molecular weight components of these tissues , since substantial evidence has accumulated that some of these smalle r proteins show a characteristic cyclic and pregnancy expression. Two specific bands were purified from homogenates of first trimester decid ua and placenta using gel filtration and anion exchange chromatography . These bands were separated by gel electrophoresis and blotting onto polyvinylidendifluoride membrane. Partial amino acid sequencing of bot h proteins revealed sequences identical to human cyclophilin A. One pr otein was sequenced -F-F-D-I-A-V-D-G-E-P-L-G-R-(X)-S-F-E-L-F-A-D-K-V-P and identified as the 17 kDa isoform of cyclophilin A. The other prot ein was sequenced V-N-P-T-V-F-F-D-I-A and identified as the 18 kDa iso form of cyclophilin A.