The Total Body Amino Acid Composition of an Animal Could Be Explained by a Mixture of the Average Composition of Its Proteome as an Intracellular Composition Estimate and the Type I Collagen Composition as an Extracellular Composition Estimate

抄録

The total amino acid composition of an animal's body is theoretically explained by the sum of the product of the amount of each protein and its amino acid composition. However, because there are so many different types of proteins, and because the amount of each protein varies greatly, it has not been easy to actually describe the total amino acid composition of the body by the sum of the amount of proteins and their compositions.

In a previous paper, I showed that the amino acid composition of cells could be mutually convergent with the average composition of the proteome proteins in the organism's genome. On the other hand, type I collagen is known to be the most abundant protein among extracellular proteins. Assuming that the intracellular amino acid composition is consistent with the average proteome composition and the extracellular amino acid composition is consistent with that of type I collagen, I investigated whether the mixture of these two compositions could describe the total body composition of an animal. In this investigation, I used body compositions of fetal pigs at different stages of gestation from the literature. As a result, I found that mixtures of these estimates of the intracellular and extracellular composition sufficiently approximated the actual total body amino acid compositions in this investigation.

Therefore, I concluded that the three assumptions that the amino acid composition of intracellular proteins approximates the average proteome composition, that the amino acid composition of extracellular proteins approximates that of type I collagen, and that the total body amino acid composition of an animal can be explained by a mixture of such intracellular and extracellular estimates, may all be correct.