Active Transport of Proline by Coxiella burnetii (original) (raw)

• _info_Info
  • Article information
  • Full-Text
  • Figures and Tables
  • References (25)
  • Cited By (9)
  • Supplementary Material
  • Metrics
• _list_Sections

Abstract

The obligate intracellular rickettsia, Coxiella burnetii, was shown to possess an energy dependent proline transport system which displayed a high degree of specificity and was highly dependent on pH. Transport was maximal at pH 3·0 to 4·5, a pH range approximating that of the host cell phagolysosome where the agent replicates. Transport was inhibited by the uncouplers carbonyl cyanide m-chlorophenylhydrazone and dinitrophenol, but not by sodium arsenite. In the presence of glutamate, a preferred energy source, proline uptake was enhanced more than two-fold. This enhancement of proline uptake was greatly decreased in the presence of sodium arsenite. The addition of glutamate decreased the apparent K m for proline transport from 45 μm to 15 μm, with the V max increasing from 3μ6 pmol s−1 (mg dry wt)−1 to 4·8 pmol s−1 (mg dry wt)−1. Two proline analogues, furoic acid and azetidine-2-carboxylic acid, were effective inhibitors of proline transport. d-Proline, 4-hydroxyproline, glycine and proline amide inhibited transport minimally, while no inhibition was seen with succinate, pyruvate or glutamate.

• Received: 07/03/1984
• Revised:26/06/1984
• Published Online:01/11/1984

© Society for General Microbiology, 1984

Article metrics loading...

/content/journal/micro/10.1099/00221287-130-11-2857

1984-11-01

2025-01-23

Full text loading...

/deliver/fulltext/micro/130/11/mic-130-11-2857.html?itemId=/content/journal/micro/10.1099/00221287-130-11-2857&mimeType=html&fmt=ahah

Most read this month

Article

content/journal/micro

Journal

5

3

false

en