Tom Richardson

Essential fatty acids in mitochondria

Abstract The fatty acid contents of mitochondria from chicken liver, beef heart, rat liver, catfish liver, carp liver, salmon liver, and salmon heart were determined by gas-liquid chromatography of the methyl esters. The degree of unsaturation of the fatty acids increased in the above order, and the molar amounts of essential fatty acids, arachidonic and linoleic acids, accounted for 22.3, 51.6, 41.0, 4.5, 20.6, 4.9, and 2.7%, respectively. Fish mitochondria were generally low in essential fatty acids, but contained high levels of docosapentaenoic and docosahexaenoic acids. Chicken liver mitochondria also contained 2.6% of a docosachexaenoic acid. Linoleic acid was very low in salmon liver mitochondria (0.9%) and salmon heart mitochondria (1.1%) and undetectable in catfish liver mitochondria. Essential fatty acid to cytochrome c molar ratios in the mitochondria ranged from 70 to 1048. It was not possible to label the fatty acids of mitochondria undergoing oxidative phosphorylation in tritium water. Added lipoxidase did not react with the unsaturated fatty acids in mitochondria and electron-transport particles. These data are discussed relative to the function of essential fatty acids in mitochondria.

Cloning And Sequence Analysis Of Bovine β-Casein cDNA

Abstract A bovine β-casein cDNA clone was isolated from a cDNA library prepared from mammary gland mRNA. Sequence analysis revealed 25 nucleotides (nt) of the 5′ noncoding region, 672 nt of the complete sequence coding and a 3′ region of approximately 500 nt. When the nucleotide sequence of bovine β-casein cDNA is compared to rat β-casein cDNA (5), a high degree of homology is observed in the first 100 nt corresponding to the signal peptide of the pre-β-caseins.

Genetic modification of food proteins

Abstract Directed alterations in the genome of food-producing organisms by deletion or addition of selected nucleic acid bases can lead to changes in the primary sequences of individual food proteins. Resulting modifications in the physico-chemical properties or enzymatic susceptibility of the altered gene product are superimposed on the endogenous normal proteins. If sufficient quantities of the novel protein are synthesized and become admixed with the basal levels of protein in the food, the functional properties of the food system (emulsification, foaming, gelling, etc.) may become enhanced. Alternatively, the modified protein might be isolated for use separately as a food ingredient. Thus genetic engineering techniques may provide the basis for production of higher quality and novel food products.