C. I. Harris

Bio: C. I. Harris is an academic researcher from University of Birmingham. The author has contributed to research in topics: Actin & Skeletal muscle. The author has an hindex of 2, co-authored 2 publications receiving 262 citations.

3-methylhistidine in actin and other muscle proteins.

Abstract: 1. By the use of the extended elution system for basic amino acid analysis, 3-methylhistidine has been detected in hydrolysates of actin isolated from mammalian, fish and bird skeletal muscle. 2. Evidence is presented to indicate that 3-methylhistidine forms part of the primary structure and that in rabbit actin this residue is restricted to one peptide fraction obtained from the tryptic digest. 3. Rabbit skeletal-muscle actin has a 3-methylhistidine:histidine ratio 1:7·6, indicating a minimum molecular weight of 47600. 4. Adult rabbit myosin contains approximately 2 3-methylhistidine residues/mol. These residues are localized in the heavy meromyosin part of the molecule, and are restricted to the major component obtained after succinylation.

Occurrence and formation of the N∈-methyl-lysines in myosin and the myofibrillar proteins

Abstract: 1. Adult rabbit skeletal-muscle myosin has been shown to contain 1.0 residue of mono-N-methyl-lysine and 3.3 residues of tri-N-methyl-lysine per molecule of molecular weight 500000. 2. The methyl-lysines appear to be located in the subfragment 1 portion of the myosin molecule. 3. Methyl-lysines are not present in actin, tropomyosin, inhibitory factor and calcium-sensitizing factor. 4. Enzymic methylation of histidine and lysine residues of myosin has been demonstrated in vitro. 5. The methylation of histidine and lysine of the total myofibrillar protein occurs after peptide-bond synthesis. 6. Although methylated lysines and 3-methyl-histidine could not be detected by analysis of hydrolysates, radiochemical evidence is provided for the presence of these residues in the soluble-protein fraction of rabbit skeletal muscle.

Actin and myosin and cell movement.

Abstract: (1974). Actin And Myosin And Cell Movemen. CRC Critical Reviews in Biochemistry: Vol. 2, No. 1, pp. 1-65.

Posttranslational covalent modification of proteins

Abstract: A search for derivatized amino acids in proteins has shown that the extent of posttranslational modification of proteins is quite substantial. While only 20 primary amino acids are specified in the genetic code and are involved as monomer building blocks in the assembly of the polypeptide chain, about 140 amino acids and amino acid derivatives have been identified as constituents of different proteins in different organisms. A brief consideration of the questions about where and when the derivatization reactions occur, how the specificity of the reactions is established, and how the posttranslational modifications can facilitate biological processes, reveal a need for more information on all these points. Answers to these questions should represent significant contributions to our understanding of biochemistry and cell biology.

An electrophoretic study of the low-molecular-weight components of myosin.

Abstract: 1. The low-molecular-weight components of myosin freshly prepared by the standard procedure from adult rabbit skeletal muscle migrated as four main bands Ml1, Ml2, Ml3 and Ml4 on polyacrylamide-gel electrophoresis in 8m-urea. 2. The number of bands increased on storage. This change was accelerated by increasing the temperature and pH. 3. None of the bands had electrophoretic mobilities identical with those of the well-characterized proteins of the myofibril or with the sarcoplasmic proteins. 4. By varying the ionic conditions and concentration of muscle mince used for the initial extraction it was possible to change the relative proportions of the two electrophoretic bands of intermediate mobility, Ml2 and Ml3. 5. The four-band picture similar to that obtained with rabbit was observed with myosin isolated from skeletal muscle of the rat, mouse, hamster, pigeon and chicken. 6. Rabbit cardiac myosin gave only two bands on electrophoresis. Myosin from rabbit red muscle gave a pattern intermediate between cardiac and white-skeletal-muscle myosin, i.e. the two fastest bands were present in decreased relative amounts. 7. It is suggested that the differences in the low-molecular-weight components of myosin from different types of muscle are a consequence of differences in the isoenzyme composition of the myosins.