Amino acid content of some proteins

protein

{{r}}

amino acid* alpha-casein gliadin edestin collagen

(ox hide) keratin

(wool) myosin

lysine 60.9 4.45 19.9 27.4 6.2 85

histidine 18.7 11.7 18.6 4.5 19.7 15

arginine 24.7 15.7 99.2 47.1 56.9 41

aspartic acid** 63.1 10.1 99.4 51.9 51.5 85

threonine 41.2 17.6 31.2 19.3 55.9 41

serine 63.1 46.7 55.7 41.0 79.5 41

glutamic acid** 153.1 311.0 144.9 76.2 99.0 155

proline 71.3 117.8 32.9 125.2 58.3 22

glycine 37.3 — 68.0 354.6 78.0 39

alanine 41.5 23.9 57.7 115.7 43.8 78

half-cystine 3.6 21.3 10.9 0.0 105.0 86

valine 53.8 22.7 54.6 21.4 46.6 42

methionine 16.8 11.3 16.4 6.5 4.0 22

isoleucine 48.8 90.8*** 41.9 14.5 29.0 42

leucine 60.3 60.0 28.2 59.9 79

tyrosine 44.7 17.7 26.9 5.5 28.7 18

phenylalanine 27.9 39.0 38.4 13.9 22.4 27

tryptophan 7.8 3.2 6.6 0.0 9.6 —

hydroxyproline 0.0 0.0 0.0 97.5 12.2 —

hydroxylysine — — — 8.0 1.2 —

total 839 765 883 1,058 863 832

average residual weight 119 131 113 95 117 120

*Number of gram molecules of amino acid per 100,000 grams of protein.

**The values for aspartic acid and glutamic acid include asparagine and glutamine, respectively.

***Isoleucine plus leucine.