The Trace Element Zinc in the Composition of Native Chorionic Gonadotropin

Human chorionic gonadotropin (hCG) is a most important regulator of embryogenesis and spermatogenesis. Equally important for the development of the fetus is the trace element zinc, which is essential for sustainable fetal development. The involvement of hCG and zinc in the first trimester of pregnancy (embryogenesis) led us to question the possibility of their structural cooperation and inclusion in the native molecule chorionic gonadotropin and zinc atoms. At the same time, we found increasing stability of the hormonal structure in the background of hCG interaction with zinc. Thus, the aim of our research was to study the possible zinc presence in the molecule of native hCG. The drug chorionic gonadotropin (1000 IU lyophilisate) was selected as the object of investigation, representing the native hormone that was derived from the urine of pregnant women. For detection of ionized zinc, we used stripping voltammetry and mass spectrometry with inductively coupled plasma at a high resolution (up to 7.10 g/L). The research of nonmineralized samples of chorionic gonadotropin lyophilisate proved its absence in free zinc. Premineralization of the samples made it possible to reveal zinc presence in nine to 17 atoms/molecule of hormone. Detecting bound zinc in the composition of native chorionic gonadotropin confirms its role as an important structural element, capable of producing compound stability and ensuring specific activity during pregnancy. The composition of native chorionic gonadotropin and a major amount of zinc in the bound state, compared to a relatively small amount of free particles, indicates the existence of the sufficiently strong intramolecular bond of hCG and zinc for maintaining active pregnancy. This fact will allow us to design methods for maintaining stable medication during pregnancy on the basis of regulation of trace-element composition in a patient's blood.