Effect of cis-unsaturated fatty acids on human leukocyte cell membrane bound enzyme activity in vitro

1992 ◽  
Vol 12 (4-5) ◽  
pp. 549-560 ◽  
Author(s):  
K Vijay Kumar ◽  
U.N. Das ◽  
K Shanti Naidu
Keyword(s):  
Fatty Acids ◽  
Enzyme Activity ◽  
Cell Membrane ◽  
Unsaturated Fatty Acids ◽  
Human Leukocyte ◽  
Membrane Bound

Inhibition of binding of gonadal steroids to serum binding proteins by non-esterified fatty acids: the influence of chain length and degree of unsaturation

1989 ◽  
Vol 120 (2) ◽  
pp. 175-179 ◽  
Author(s):  
C. Street ◽  
R. J. S. Howell ◽  
L. Perry ◽  
S. Al-Othman ◽  
T. Chard
Keyword(s):  
Fatty Acids ◽  
Protein Binding ◽  
Unsaturated Fatty Acids ◽  
Late Pregnancy ◽  
Sex Hormone Binding Globulin ◽  
Partial Purification ◽  
Normal Female ◽  
Esterified Fatty Acids ◽  
Vitro Binding

Abstract. The effect of non-esterified fatty acids (NEFA) on the in vitro binding of testosterone, 5-alpha dihydrotestosterone and estradiol E2 to sex hormone binding globulin (SHBG) was examined using pooled normal female serum, and SHBG and albumin fractions obtained from the partial purification of late pregnancy serum. A range of saturated and unsaturated fatty acids were examined for their effect on steroid-protein binding. In normal female serum, NEFA added at physiological concentrations disrupted steroid-protein binding. The shorter chain (C8–C12) saturated acids and the poly-unsaturated acids proved to be more effective inhibitors than the longer chain saturated or mono-unsaturated acids. The greatest inhibition was obtained with E2 whereas the binding of dihydrotestosterone was least affected. With partially purified SHBG, the same concentrations of NEFA were less effective at inhibiting the binding of dihydrotestosterone and testosterone but elicited the same effect with E2. The binding of steroids to albumin appeared to be unaffected by these concentrations of NEFA.

scholarly journals A kinetic rationale for functional redundancy in fatty acid biosynthesis

2020 ◽  
Vol 117 (38) ◽  
pp. 23557-23564
Author(s):  
Alex Ruppe ◽  
Kathryn Mains ◽  
Jerome M. Fox
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Unsaturated Fatty Acids ◽  
Fatty Acid Biosynthesis ◽  
Average Length ◽  
Functional Redundancy ◽  
Experimental Investigations ◽  
Total Production

Cells build fatty acids with biocatalytic assembly lines in which a subset of enzymes often exhibit overlapping activities (e.g., two enzymes catalyze one or more identical reactions). Although the discrete enzymes that make up fatty acid pathways are well characterized, the importance of catalytic overlap between them is poorly understood. We developed a detailed kinetic model of the fatty acid synthase (FAS) ofEscherichia coliand paired that model with a fully reconstituted in vitro system to examine the capabilities afforded by functional redundancy in fatty acid synthesis. The model captures—and helps explain—the effects of experimental perturbations to FAS systems and provides a powerful tool for guiding experimental investigations of fatty acid assembly. Compositional analyses carried out in silico and in vitro indicate that FASs with multiple partially redundant enzymes enable tighter (i.e., more independent and/or broader range) control of distinct biochemical objectives—the total production, unsaturated fraction, and average length of fatty acids—than FASs with only a single multifunctional version of each enzyme (i.e., one enzyme with the catalytic capabilities of two partially redundant enzymes). Maximal production of unsaturated fatty acids, for example, requires a second dehydratase that is not essential for their synthesis. This work provides a kinetic, control-theoretic rationale for the inclusion of partially redundant enzymes in fatty acid pathways and supplies a valuable framework for carrying out detailed studies of FAS kinetics.

scholarly journals Characterization of the unique In Vitro effects of unsaturated fatty acids on the formation of amyloid β fibrils

PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0219465 ◽  
Author(s):  
Miki Eto ◽  
Tadafumi Hashimoto ◽  
Takao Shimizu ◽  
Takeshi Iwatsubo
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Amyloid Β ◽  
In Vitro Effects

The Effect of Fatty Acids upon Tumor Cell Respiration and Transplantability

1963 ◽  
Vol 9 (5) ◽  
pp. 530-543 ◽  
Author(s):  
Bernard J Katchman ◽  
Robert E Zipf ◽  
James P F Murphy
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Tumor Cells ◽  
Chemical Structure ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Leukemic Cells ◽  
Endogenous Respiration ◽  
Low Concentrations

Abstract The kinetic effect of palmitate, stearate, oleate, linoleate, and linolenate upon in vitro endogenous respiration of rat chloromyeloid leukemic cells has been investigated. Inhibition of respiration has been correlated with the ability of fatty acids to cause decreased cell viability and cell count; in the bioassay of fatty acid-treated tumor inocula, the increase in animal life span is correlated to the degree of dilution of the inocula due to cell lysis. The degree of lysis is dependent upon the chemical structure of the fatty acid, concentration, and duration of contact; unsaturated fatty acids are more effective than saturated fatty acids. Tumor cells, when incubated at low concentrations of fatty acids, show stimulation of O2 uptake; however, in the bioassay these fatty acid-treated inocula showed no loss in tumor activity. The nature of the physiochemical interaction between fatty acids and tumor cells is discussed.

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