Purification, composition, and structure of macrophage adhesion molecule
Macrophage adhesion molecule (MAM) is a surface heterodimer consisting of the trypsin- and plasmin-sensitive glycopeptide gp160 (MAM-..cap alpha..) and the glycopeptide gp93 (MAM-..beta..). MAM, which is the guinea pig analog of Mo1 and Mac-1, was purified from detergent lysates of peritoneal neutrophils by lentil lectin chromatography and M2-antibody chromatography. The pure heterodimer molecule was dissociated by acidic conditions (pH 3.5), and MAM-..cap alpha.. and MAM-..beta.. were separated by M7-antibody chromatography. MAM-..beta.. is an approx. 640 amino acid residue polypeptide with exceptionally high cysteine content. At 7.2 residues per 100 amino acids, Cys/2 of MAM-..beta.. is more than 3 times the mean for 200 purified proteins. Reactivity with six ..beta..-subunit-specific /sup 125/I-labeled monoclonal antibodies recognizing at least four epitopes demonstrated that intrapeptide disulfide bonds are required to maintain the structure of MAM-..beta... All six antibodies failed to react when MAM-..beta.. was treated with reducing agents. MAM-..beta.. is 18% carbohydrate; the major monosaccharides are mannose, N-acetylglucosamine, galactose, and sialic acid. MAM-..beta.. is estimated to contain five to six N-linked carbohydrate units. MAM-..cap alpha.. is an approx. 1100-residue polypeptide with lower Cys/2 content (2.0 residues per 100 amino acid residues). MAM-..cap alpha.. is 21% carbohydrate. The major monosaccharides are mannose, N-acetylglucosamine, galactose, and sialic acid; the mannose content is higher in MAM-..cap alpha.. than MAM-..beta.. is estimated to contain 12 N-linked carbohydrate units.
- Research Organization:
- Center for Blood Research, Boston, MA
- OSTI ID:
- 5357856
- Journal Information:
- Biochemistry; (United States), Vol. 27:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Characterization of macrophage adhesion molecule
Structural analysis of the asparagine-linked oligosaccharides of cholinesterases. N-linked carbohydrates of cholinesterases
Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
GLUCOPROTEINS
CROSS-LINKING
MOLECULAR STRUCTURE
PURIFICATION
MACROPHAGES
AUTORADIOGRAPHY
MONOCLONAL ANTIBODIES
AMINO ACID SEQUENCE
ELECTROPHORESIS
IMMUNOLOGY
IODINE 125
ANIMAL CELLS
ANTIBODIES
BETA DECAY RADIOISOTOPES
CARBOHYDRATES
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHAGOCYTES
POLYMERIZATION
PROTEINS
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS
550201* - Biochemistry- Tracer Techniques
550601 - Medicine- Unsealed Radionuclides in Diagnostics