Abstract

SummaryMouse peritoneal macrophages in culture released a macromolecular factor capable of inhibiting mouse L1210 lymphoma cells in vitro. The factor was proved to be arginase by several criteria. The inhibition was reversed by adding arginine or citrulline to culture, the arginine in the culture medium was consumed, and the guanido group of arginine was hydrolyzed exclusively to urea as demonstrated by electrophoresis and chromatography. The factor has a molecular weight of 110,000 and a Km value of 1.0 × 10-2M. These and other parameters, such as a requirement for Mn2+, alkaline pH optimum, substrate specificities, and inhibition by ornithine, were similar to those of liver arginases. The arginine in the medium was decomposed by first-order kinetics, and the arginase activity in the supernatant of 10 × 106 peritoneal exudate cells/ml was enough to deplete arginine in the medium to below the level required for L1210 cells to grow in culture.Arginase activity was also detected in the peritoneal washing fl...

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.