Long-chain free fatty acids: Semiochemicals for host location by western corn rootworm larvae

1994 ◽  
Vol 20 (12) ◽  
pp. 3335-3344 ◽  
Author(s):  
Bruce E. Hibbard ◽  
Elisa J. Bernklau ◽  
Louis B. Bjostad
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Host Location ◽  
Western Corn Rootworm ◽  
Corn Rootworm ◽  
Long Chain

scholarly journals Free Fatty Acids Interfere with the DNA Binding Activity of the Virulence Regulator PrfA of Listeria monocytogenes

2020 ◽  
Vol 202 (15) ◽  
Author(s):  
Patrícia T. dos Santos ◽  
Rikke S. S. Thomasen ◽  
Mathias S. Green ◽  
Nils J. Færgeman ◽  
Birgitte H. Kallipolitis
Keyword(s):  
Fatty Acids ◽  
Dna Binding ◽  
Free Fatty Acids ◽  
Antimicrobial Agents ◽  
Virulence Gene ◽  
Binding Activity ◽  
Content Type ◽  
Dna Binding Activity ◽  
Virulence Regulator ◽  
Long Chain

ABSTRACT Naturally occurring free fatty acids (FFAs) are recognized as potent antimicrobial agents that also affect the production of virulence factors in bacterial pathogens. In the foodborne pathogen Listeria monocytogenes, some medium- and long-chain FFAs act as antimicrobial agents as well as signaling compounds, causing a repression of transcription of virulence genes. We previously observed that the master virulence regulator PrfA is involved in both the antimicrobial and virulence-inhibitory response of L. monocytogenes to selected FFAs, but the underlying mechanisms are presently unknown. Here, we present a systematic analysis of the antimicrobial and PrfA-inhibitory activities of medium- and long-chain FFAs of various carbon chain lengths and degrees of saturation. We observed that exposure to specific antimicrobial and nonantimicrobial FFAs prevented PrfA-dependent activation of virulence gene transcription and reduced the levels of PrfA-regulated virulence factors. Thus, an antimicrobial activity was not compulsory for the PrfA-inhibitory ability of an FFA. In vitro binding experiments revealed that PrfA-inhibitory FFAs were also able to prevent the constitutively active variant PrfA* from binding to the PrfA box in the promoter region of the virulence gene hly, whereas noninhibitory FFAs did not affect its ability to bind DNA. Notably, the unsaturated FFAs inhibited the DNA binding activity of PrfA* most efficiently. Altogether, our findings support a model in which specific FFAs orchestrate a generalized reduction of the virulence potential of L. monocytogenes by directly targeting the key virulence regulator PrfA. IMPORTANCE Listeria monocytogenes is a Gram-positive pathogen able to cause foodborne infections in humans and animals. Key virulence genes in L. monocytogenes are activated by the transcription regulator PrfA, a DNA binding protein belonging to the CRP/FNR family. Various signals from the environment are known to affect the activity of PrfA, either positively or negatively. Recently, we found that specific medium- and long-chain free fatty acids act as antimicrobial agents as well as signaling compounds in L. monocytogenes. Here, we show that both antimicrobial and nonantimicrobial free fatty acids inhibit PrfA-dependent activation of virulence gene transcription by interfering with the DNA binding activity of PrfA. Our findings suggest that free fatty acids could be candidates for alternative therapies against L. monocytogenes.

Long-chain acyl CoA's and free fatty acids in rat brain after head injury

1997 ◽  
Vol 237 ◽  
pp. S25
Author(s):  
H. Heller ◽  
J. Deutsch ◽  
A.D. Purdon ◽  
S.I. Rapoport ◽  
M. Horowitz ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Head Injury ◽  
Free Fatty Acids ◽  
Rat Brain ◽  
Chain Acyl ◽  
Long Chain

A new pyrolytic process with potential to convert free fatty acids into long chain nitriles and H2 intermediated by Fe nitrate

2020 ◽  
Vol 145 ◽  
pp. 104726
Author(s):  
Fabiano Gomes Ferreira de Paula ◽  
Rafael César Gonçalves Pereira ◽  
Breno Frederico Pereira Paulo ◽  
José Domingos Ardisson ◽  
Zenilda de Lourdes Cardeal ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Long Chain
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