In vitro Incorporation of G 14 Glycine and S 35 Sulfate into Protein by Human Colon Mucosa. ∗

Summary

1. The incorporation of car-boxyl C¹⁴ labeled glycine into the protein of human colon mucosa has been studied in vitro. The incorporation was inhibited by nitrogen and cyanide. There was no consistent effect from omitting calcium and/or magnesium from the buffer. Penicillin depressed the incorporation: aureomycin produced no consistent results. Homogenized tissue failed to incorporate even though viable bacteria were present. 2. A mucoprotein was isolated from colon mucosa and both carboxyl C¹⁴ glycine and inorganic S³⁵ sulfate were found to be incorporated into protein and mucoprotein. 3. Solution and reprecipitation of total crude protein removed the S³⁵ label, but not the C¹⁴ label.