Search
Filter Results
- Resource Type
- Article1
- Book1
- Book Digital1
- Result From
- Lane Catalog1
- PubMed1
-
Year
- Journal Title
- J Gen Microbiol1
Search Results
Sort by
- ArticleBell G, Payne GM, Payne JW.J Gen Microbiol. 1977 Feb;98(2):485-91.A new method has been developed for measuring peptide transport in aminoacid auxotrophs of Escherichia coli by following induction of beta-galactosidase. Appearance of the enzyme was determined after addition of inducer and peptides to amino-acid starved bacteria. For a given number of lysine equivalents, the rate and the extent of enzyme synthesis were the same for lysine and lysyl peptides; similar results were found for glycine and glycl peptides. Saturation constants for peptide transport were determined from the exogenous peptide concentration that gave half maximal rates of enzyme synthesis. The saturation constants, studies with mutants defective in peptide transport, and detection of competition between peptides for uptake, all endorsed earlier conclusions from growth tests about the structural specificities for peptide transport. The new method is quicker, more sensitive and more informative than growth tests.