Simultaneous Isolation of Prolactin and Growth Hormone from “Discarded Acid Pellet” Obtained from Buffalo Pituitaries

Abstract

An acid pellet, obtained as a side fraction from a conventional gonadotropin purification pathway, has been found to contain the bulk of the pituitary lactogenic hormones (growth hormone or GH and prolactin or PRL). This discarded side fraction has been utilized to obtain buffalo lactogenic hormones (buGH and buPRL), simultaneously, and in bulk. The immunoreactivities of the purified semi‐pure buffalo GH and PRL (APECS and APP‐I, respectively) preparations were compared by direct binding ELISA with semi‐pure standard buGH and PRL (ECS and EP‐I, respectively) and were found to be as pure as standard semi‐pure buGH and buPRL. When checked by direct binding ELISA using buGH and buPRL antisera, it was observed that APECS and APP‐I were not cross‐immunoreactive. SDS‐PAGE and western blot analysis of APECS and APP‐I showed major bands located at the same positions as in the case of standard semi‐pure preparations (20 kDa for APECS and 23 kDa for APP‐I). The semi‐purified buGH and buPRL (APECS and APP‐I) were converted to a highly purified preparation by chromatographing them via Sephacryl S‐200 gel‐filtration chromatography.