Purification of homologous protein carboxyl methyltransferase isozymes from human and bovine erythrocytes

Journal Article · Tue Jul 12 00:00:00 EDT 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00414a042· OSTI ID:7188189

Gilbert, J M; Fowler, A; Bleibaum, J; Clarke, S

The authors have purified the two major isozymes of the L-isoaspartyl/D-aspartyl protein methyltransferase from both human and bovine erythrocytes. These four enzymes all have polypeptide molecular weights of approximately 26,500 and appear to be monomers in solution. Each of these enzymes cross-reacts with antibodies directed against protein carboxyl methyltransferase I from bovine brain. Their structures also appear to be similar when analyzed by dodecyl sulfate gel electrophoresis for the large fragments produced by digestion with Staphylococcus aureus protease V8 or when analyzed by high-performance liquid chromatography (HPLC) for tryptic peptides. The structural relatedness of these enzymes was confirmed by sequence analysis of a total of 433 residues in 32 tryptic fragments of the human erythrocyte isozymes I and II and of the bovine erythrocyte isozyme II. They found sequence identity or probable identity in 111 out of 112 residues when they compared the human isozymes I and II and identities in 127 out of 134 residues when the human and bovine isozymes II were compared. These results suggest that the erythrocyte isozymes from both organisms may have nearly identical structures and confirm the similarities in the function of these methyltransferases that have been previously demonstrated.

• Research Organization: Univ. of California, Los Angeles (USA)
• OSTI ID: 7188189
• Journal Information: Biochemistry; (United States), Vol. 27:14
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
METHYL TRANSFERASES
AMINO ACID SEQUENCE
ISOENZYMES
PURIFICATION
AUTORADIOGRAPHY
BIOCHEMISTRY
CATTLE
ELECTROPHORESIS
ERYTHROCYTES
LIQUID COLUMN CHROMATOGRAPHY
MAN
TRITIUM COMPOUNDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHEMISTRY
CHROMATOGRAPHY
DOMESTIC ANIMALS
ENZYMES
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MOLECULAR STRUCTURE
PRIMATES
RUMINANTS
SEPARATION PROCESSES
TRANSFERASES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques