Factors influencing the pattern of fatty acids synthesized by cell-free preparations of lactating rat mammary gland
| Autor: | J. C. Bartley, S. Abraham, I.L. Chaikoff |
|---|---|
| Rok vydání: | 1967 |
| Předmět: |
Ammonium sulfate
Chromatography Gas Biophysics Fraction (chemistry) Acetates Biochemistry Ligases chemistry.chemical_compound Mammary Glands Animal Endocrinology Pregnancy Microsomes Animals Lactation Coenzyme A Citrates Incubation chemistry.chemical_classification Carbon Isotopes Chromatography Fatty Acids Fatty acid Rat Mammary Gland Malonates Rats Pyruvate carboxylase chemistry Microsome Female Saturation (chemistry) |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 144:51-60 |
| ISSN: | 0005-2760 |
| DOI: | 10.1016/0005-2760(67)90076-8 |
| Popis: | 1. 1. The pattern of fatty acids synthesized from [1- 14 C]acetate, [1- 14 C]acetyl-CoA, [1,5- 14 C 2 ]citrate and [l,3- 14 C 2 ]malonyl-CoA by various homogenate preparations of mammary glands of lactating rats was studied with the aid of gas-liquid chromatography. 2. 2. Addition of microsomes to the 100000× g supernatant fraction significantly decreased the incorporation of labeled acetate into C 10 and C 12 fatty acids and increased that into C 16 and C 18 acids. 3. 3. When [ 14 C]acetate or acetyl-CoA were the substrates in experiments with the 100000× g supernatant fraction, the isotope was incorporated predominantly into C 10 fatty acid. The labeled malonyl-CoA was predominantly converted to C 16 fatty acid. The pattern of incorporation of the 14 C of [1,5- 14 C 2 ]citrate was intermediate between these two. 4. 4. When an ammonium sulfate fraction of the 100000× g supernatant fluid, precipitating between 0 and 40% saturation, was used as the source of acetyl-CoA carboxylase (EC 6.4.1.2) and fatty acid synthetase, the pattern of conversion of all labeled substrates to fatty acids was the same, i.e., predominautely to C 16 acids. Addition of fractions precipitating at higher satuiations of ammonium sulfate had no effect on the pattern of conversion. 5. 5. When the ammonium sulfate fraction (0–29% saturation) rich in acetyl-CoA carboxylase was added to incubation mixtures containing a constant amount of a fraction (29–40% saturation) rich in fatty acid synthetase, the average chain length of the fatty acids synthesized from acetyl-CoA was decreased as the concentration of acetyl-CoA carboxylase was decreased, but the chain length of the fatty acids formed from the labeled malonyl-CoA was unchanged. 6. 6. The results indicate that the concentration of malonyl-CoA is a factor in determining the pattern of fatty acids formed by mammary gland. The mechanism for expression of this influence is discussed, along with other factors that might affect the pattern of fatty acids synthesized. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|