Transport of. cap alpha. -aminoisobutyric acid by Streptococcus pyogenes and its derived L-form

Journal Article · Fri Jan 01 00:00:00 EST 1982 · J. Bacteriol.; (United States)

OSTI ID:5759101

Reizer, J; Panos, C

We studied the uptake of ..cap alpha..-aminoisobutyric acid (AIB) in Streptococcus pyogenes and its physiologically isotonic L-form. S. pyogenes cells starved for glucose or treated with carbonyl cyanide-m-chlorophenyl hydrazone accumulated limited amounts of AIB. A high apparent K/sub m/ value characterized the glucose-independent transport of AIB. The rate and extent of AIB accumulation significantly increased in the presence of glucose. Two saturable transport components with distinct apparent K/sub m/values characterized glycolysis-coupled transport of AIB. A biphasic Lineweaver-Burk plot was also obtained for L-alanine transport by glycolyzing S. pyogenes cells. AIB seems to share a common transport system(s) with glycine, L- and D-anine, L-serine, and L-valine. This was shown by the competitive exchange efflux of accumulated AIB. About 30% of the AIB uptake was not inhibited by a saturating amount of L-valine, indicating the existence of more than one system for AIB transport, p-Chloromercuribenzoate markedly inhibited the accumulation of AIB by both glycolyzing and glucose-starved cells. In contrast, carbonyl cyanide-m-chlorophenyl hydrazone affected only metabolism-dependent uptake of AIB, which was also sensitive to dinitrophenol, N-ethylmaleimide, iodoacetate, fluoride (NaF), arsenate, and N,N'-dicyclohexylcarbodiimide. These results are interpreted according to the chemiosmotic theory of Mitchell, whereby a proton motive force constitutes the driving force for AIB accumulation. AIB was not accumulated by the L-form. However, a temporary accumulation of AIB by a counterflow mechanism and a saturable system with a low apparent affinity were demonstrated for AIB transport by this organism. We suggest that a deficiency in the coupling of energy to AIB transport is responsible for the apparent lack of active AIB accumulation by the L-form.

• Research Organization: Thomas Jefferson University, Philadelphia, PA
• OSTI ID: 5759101
• Journal Information: J. Bacteriol.; (United States), Vol. 149:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BUTYRIC ACID
METABOLISM
UPTAKE
INHIBITION
ARSENATES
BIOLOGICAL PATHWAYS
CHLORINE COMPOUNDS
DINITROPHENOL
EXPERIMENTAL DATA
FLUORIDES
GLUCOSE
GLYCOLYSIS
MERCURY COMPOUNDS
RESPONSE MODIFYING FACTORS
SENSITIVITY
STREPTOCOCCUS
ALDEHYDES
AROMATICS
ARSENIC COMPOUNDS
BACTERIA
CARBOHYDRATES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DATA
DECOMPOSITION
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HEXOSES
HYDROXY COMPOUNDS
INFORMATION
MICROORGANISMS
MONOCARBOXYLIC ACIDS
MONOSACCHARIDES
NITRO COMPOUNDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHENOLS
SACCHARIDES
550700* - Microbiology