Transport of B-Vitamins in Microorganisms. III. Chromatographic Studies on the Radioactivity Extracted from Non-proliferating Cells of Lactobacillus fermenti after Exposure to Labelled Thiamine.

Neujahr, Halina Y.; Bergman, B; Nevald, R.; Frank, Vered; Brunvoll, J.; Bunnenberg, E.; Djerassi, Carl; Records, Ruth

doi:10.3891/acta.chem.scand.20-0786

Cited by 9 publications

(4 citation statements)

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“…Similar results were also obtained in other preparations (4,11,18). The nature of the transport system is similar to that demonstrated in the small intestine (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14), central nervous system (15)(16)(17)(18) and microorganisms (20)(21)(22)(23). The transport system for thiamine requires the presence of oxygen and is sodium dependent.…”

Section: Discussionmentioning

confidence: 60%

Active transport of thiamine by freshly isolated rat hepatocytes.

Chen

1978

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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SummaryRat hepatocytes were freshly prepared from adult animals using the collagenase-perfusion technique. The hepatic transport of thiamine was studied in isolated liver cells. The process was found to be saturable with an apparent Kt of 0.31mM and a Vmax of 0.7 umoles/ml intracellular fluid/5 minutes. However, at higher substrate concentrations, the process proceeded in a linear fashion. Both pyrithiamine and oxythiamine were inhibitory on the hepatic uptake of thiamine, the latter showed much weaker activity than the former. The system required the presence of sodium ions and was sensitive to ouabain. Anaerobic condition and metabolic inhibitors, e.g., 2,4-dinitrophenol, cyanide, and iodoacetate suppressed the uptake rate of thiamine. Addition of ethanol in the incubation medium also caused significant reduction of thiamine uptake. Efflux studies indicated that a portion of intracellular thiamine is readily available for exodus. Chromatographic analyses showed that thiamine was only slightly metabolically altered during the transport process. It is suggested that thiamine is transported into isolated hepatic cells by an active, sodium-dependent process.

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Section: Discussionmentioning

confidence: 60%

Active transport of thiamine by freshly isolated rat hepatocytes.

Chen

1978

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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“…35:1357, 1976), we demonstrated that L. casei cells have the ability to transport several other B-vitamins, including thiamine. When examined in more detail, the thiamine transport system of L. casei was found to be similar in many respects to the thiamine uptake systems in both L. fermentii (14)(15)(16)(17) and Escherichia coli (9,10,18). L. casei also contains considerable amounts of a thia-mine-binding activity which can be detected by the same procedure (5) employed to measure folate binding by these cells.…”

mentioning

confidence: 85%

“…When the uptake of thiamine after 10 min at 37°C was corrected for both the small amount of vitamin converted to its phosphorylated forms and the amount of vitamin bound by the cells, the ratio of the internal and external thiamine concentrations was approximately 40. In both E. coli (9) and L. fermentii (14)(15)(16), free thiamine does not accumulate but is converted rapidly to thiamine pyrophosphate upon entry into the cell. However, mutant studies have shown that, at least in E. coli, energy can be used to achieve concentration gradients for free thiamine (10).…”

Section: Inhibition Of ['4cmentioning

confidence: 99%

Binding and transport of thiamine by Lactobacillus casei

Henderson¹,

Zevely²

1978

J Bacteriol

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The relationship between thiamine transport and a membrane-associated thiamine-binding activity has been investigated in Lactobacillus casei. Thiamine transport proceeds via a system whose general properties are typical of active uptake processes; entry of the vitamin into the cells requires energy, is temperature dependent, exhibits saturation kinetics, and is inhibited by substrate analogs. A considerable concentration gradient of unchanged thiamine can be achieved by the system, although the vitamin is slowly metabolized to thiamine pyrophosphate. Consistent with these results, L. casei also contains a high-affinity, thiamine-binding component which could be measured by incubation of intact cells with labeled substrate at 4°C (conditions under which transport is negligible). Binding was insensitive to iodoacetate, occurred at a level (0.5 nmol per 1010 cells) nearly 20-fold higher than could be accounted for by facilitated diffusion, and was found to reside in a component of the cell membrane. Participation of this binder in thiamine transport is supported by the observations that the processes of binding and transport showed similarities in their (i) regulation by the concentration of thiamine in the growth medium, (ii) binding affinities for thiamine, and (iii) susceptibility to inhibition by thiamine analogs.

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“…These two permease systems are most probably independent of each other since cocci of strain D 1560, which are unable to concentrate the thiazole moiety, nevertheless have enough intracellular pyrimidine moiety for co-enzyme synthesis. The existence of a permease for thiamine in Lactobacillus fermenti has recently been shown in a convincing way (Neujahr, 1966).…”

Section: -2mentioning

confidence: 97%

Metabolic Disorders in Thiamineless Dwarf Strains of Staphylococcus aureus

Sompolinsky

Ernst-Geller

Segal

1967

Journal of General Microbiology

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SUMMARYDwarf colony variants of Staphylococcus aureus have been described as a causative agent of bovine mastitis in Israel. These strains were reported as auxotrophic for thiamine, being unable to synthesize the vitamin from its pyrimidine and thiazole moieties. In the present paper it is shown that strains with two different deficiencies are involved. One type is unable to concentrate the thiazole moiety and the other is unable to phosphorylate the pyrimidine portion of the vitamin. The results indicate the existence of independent permeases in S. aureus for these thiamine moieties.

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Transport of B-Vitamins in Microorganisms. III. Chromatographic Studies on the Radioactivity Extracted from Non-proliferating Cells of Lactobacillus fermenti after Exposure to Labelled Thiamine.

Cited by 9 publications

References 0 publications

Active transport of thiamine by freshly isolated rat hepatocytes.

Active transport of thiamine by freshly isolated rat hepatocytes.

Binding and transport of thiamine by Lactobacillus casei

Metabolic Disorders in Thiamineless Dwarf Strains of Staphylococcus aureus

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