[Animal analogs of human embryonal prealbumin-2].
Immunochemical analogs of human embryonal prealbumin-2 (EPA-2) were found in blood sera and amniotic fluid of the cow, sheep and pig fetuses. Meanwhile they were not detected in blood sera of adult animals. Analogs of animal EPA-2 produced the reaction of complete immunochemical identity with human EPA-2. Moreover, they have similar physicochemical properties and electrophoretic mobility of prealbumins. The indirect immunofluorescence technique was used to locate EPA-2 in collagenic fibres of fetuses and in adult animals' connective tissue. It is suggested that EPA-2 might be the protein contained by procollagen or by non-collagenic components of collagenic fibres.