Date of Award


Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

Lioyd Wolfinbarger, Jr.

Committee Member

Roy L. Williams

Committee Member

Kenneth D. Somers

Call Number for Print

Special Collections LD4331.B46 C371


The dipeptides glycyl-L-(3H)-leucine and L-phenylalanyl-L-(3H)-leucine were synthesized in radioactive form and utilized in the analysis of peptide transport and hydrolysis by Ehrlich ascites tumor cells. The tumor cells were cultured in the abdominal cavity of CF-1 albino mice and harvested into sterile isotonic buffer for all experimental analyses.

The results of this study reveal that the tumor cells rapidly accumulate radiolabel when incubated with the above mentioned peptides, but that the peptide is most probably hydrolyzed extracellularly and free L-(3)-leucine transported. This hypothesis is based on the observations of reduction in accumulation of radiolabel by free leucine, but not by other peptides, and that only L-(3H)-leucine is found intracellularly.

Extracellular and intracellular peptidase activities associated with the tumor cells are high. Polyacrylamide gel electrophoresis with "in situ” activity staining revealed six major bands of peptidase activity in the cytoplasmic component. The non-fractionated extracellular peptidase activity hydrolyzed all peptides tested except for those peptides containing beta-alanyl residues.


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