Purification, composition, and structure of macrophage adhesion molecule

Journal Article · Tue Jan 12 04:00:00 EST 1988 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00401a008· OSTI ID:5357856

Remold-O'Donnell, E; Savage, B

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), Journal Name: Biochemistry; (United States) Vol. 27:1; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

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59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINO ACID SEQUENCE
ANIMAL CELLS
ANTIBODIES
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
CARBOHYDRATES
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
GLUCOPROTEINS
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
MACROPHAGES
MOLECULAR STRUCTURE
MONOCLONAL ANTIBODIES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHAGOCYTES
POLYMERIZATION
PROTEINS
PURIFICATION
RADIOISOTOPES
SACCHARIDES
SOMATIC CELLS