Cells of an Escherichia coli mutant defective in heme biosynthesis (hemA) grown under conditions for respiration deficiency (grown in the absence of aminolevulinic acid) have 20% of the number of specific colicin Ia receptors found in cells of the same strain grown under conditions for respiration competency (grown in the presence of aminolevulinic acid).

5-Aminolevulinic acid is incubated with a crude enzyme extract from Rhodopseudomonas spheroides, mutant R 26. The formed porphyrins (main product: uroporphyrin III) are isolated. Incorporation o f iron, ring-splitting by coupled oxydation and subsequent iron removal leads to a mixture o f pigments, from which urobiliverdin, a new bile pigment with eight carboxylic acid side chains, is isolated....

The effect of 5 drugs on the transport of several substrates, including the chemotherapeutic agent nitrogen mustard; choline; two nonmetabolizable amino acids, a-aminoisobutyric acid and cycloleucine; the glucose analog, 3-0-methyl-Dglucose; and the heme precursor, 6-aminolevulinic acid; was undertaken in L5178Y murine lymphoblasts in vitro. Trans port of both hydrolyzed nitrogen mustard and ch...