The amino-acid composition of rabbit myosin

Abstract

THE studies of Weber [1933] and others have proved that the intracellular protein of muscle consists of at least three distinct fractions, the globulin myosin, the albumin myogen and globulin X. To these must be added the myoalbumin fraction recently isolated by Smith [1937], although this fraction has not yet been obtained in its native state. According to Smith, the distribution of the intracellular protein of rabbit's muscle is: 67-5 % myosin, 9 % myogen. 22-5 % globulin X and 1 % myoalbumin. Table I. Amino-acid analysis of rabbit myo8in N% Wt. % Amino-acid protein-N protein Glycine 2-1 1.9 Alanine 3.5 3-7 Valine 2-2 3 0 Leucines 7-1 11.1 Proline 0 4 0'5 Phenylalanine 2.0 4 0 Threonine 0 9 1-2 *Methionine 1.9 3.4 *Cystine 0-56 0-77 *Tyrosine 1-6 3.4 *Tryptophan 0-66 0-82 Arginine 13*4 7.0 Histidine 2-8 1-7 Lysine 11-3 9.9 Glutamic acid 12-5 22-1 Aspartic acid 5-6 8-9 Ammonia 7-9 1-6 Total accounted for 76-4 85-0 * From Bailey [1937].