Aminopeptidase N in sera of healthy subjects is a different N-terminal processed derivative from the one obtained from maternal serum.
A major aminopeptidase present in normal human serum was purified to homogeneity as a 150-kDa molecular species. Western blotting confirmed the binding of an anti-aminopeptidase N antibody to the protein. The N-terminal amino acid sequence of the enzyme was determined. The first 13 amino acids of the enzyme completely matched amino acids 59-71 of the sequence predicted from the human intestinal aminopeptidase N cDNA nucleotide sequence. As reported previously, aminopeptidase N from maternal serum had 68 fewer amino acid residues at the N-terminus than the enzyme obtained from detergent-solubilized membranes. The results indicate that aminopeptidase N in normal serum is a different N-terminal processed derivative from that obtained from maternal serum.
Watanabe
Y
Y
Department of Clinical Biochemistry, Hokkaido College of Pharmacy, Japan.
Ito
K
K
Iwaki-Egawa
S
S
Yamaguchi
R
R
Fujimoto
Y
Y
D000595:Amino Acid Sequence; D001665:Binding Sites; D018826:CD13 Antigens / Q000097:blood* / Q000302:isolation & purification / Q000378:metabolism; D010450:Endopeptidases; D005260:Female; D006801:Humans; D006868:Hydrolysis; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008565:Membrane Proteins / Q000097:blood / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000097:blood / Q000302:isolation & purification / Q000378:metabolism; D011247:Pregnancy; D011499:Protein Processing, Post-Translational; D017421:Sequence Analysis; D015032:Zinc / Q000378:metabolism
D008565:Membrane Proteins; D010446:Peptide Fragments; D010450:Endopeptidases; D018826:CD13 Antigens; D015032:Zinc