Isolation and primary structure of NGAL, a novel protein associated with human neutrophil gelatinase

J Biol Chem. 1993 May 15;268(14):10425-32.


A 25-kDa protein was found to be associated with purified human neutrophil gelatinase. Polyclonal antibodies raised against gelatinase not only recognized gelatinase but also this 25-kDa protein. Specific antibodies against the 25-kDa protein were obtained by affinity purification of the gelatinase antibodies. Immunoblotting and immunoprecipitation studies demonstrated the 135-kDa form of gelatinase to be a complex of 92-kDa gelatinase and the 25-kDa protein, and the 220-kDa form was demonstrated to be a homodimer of the 92-kDa protein, thus explaining the 220-, 135-, and 92-kDa forms characteristic of neutrophil gelatinase. The 25-kDa protein was purified to apparent homogeneity from exocytosed material from phorbol myristate acetate-stimulated neutrophils. The primary structure of the 25-kDa protein was determined as a 178-residue protein. It was susceptible to treatment with N-glycanase, and one N-glycosylation site was identified. The sequence did not match any known human protein, but showed a high degree of similarity with the deduced sequences of rat alpha 2-microglobulin-related protein and the mouse protein 24p3. It is thus a new member of the lipocalin family. The function of the 25-kDa protein, named neutrophil gelatinase-associated lipocalin (NGAL), remains to be determined.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute-Phase Proteins*
  • Alpha-Globulins / chemistry
  • Amino Acid Sequence
  • Animals
  • Antibodies
  • Blotting, Western
  • Carrier Proteins / blood*
  • Carrier Proteins / chemistry
  • Carrier Proteins / isolation & purification*
  • Chromatography, Liquid
  • Collagenases / chemistry
  • Collagenases / isolation & purification*
  • Electrophoresis, Polyacrylamide Gel
  • Glycoproteins / blood*
  • Glycoproteins / isolation & purification*
  • Glycoside Hydrolases
  • Humans
  • Lipocalin-2
  • Lipocalins
  • Macromolecular Substances
  • Matrix Metalloproteinase 9
  • Mice
  • Molecular Sequence Data
  • Molecular Weight
  • Neutrophils / drug effects
  • Neutrophils / enzymology*
  • Oncogene Proteins*
  • Proto-Oncogene Proteins
  • Rats
  • Sequence Homology, Amino Acid
  • Tetradecanoylphorbol Acetate / pharmacology


  • Acute-Phase Proteins
  • Alpha-Globulins
  • Antibodies
  • Carrier Proteins
  • Glycoproteins
  • LCN2 protein, human
  • Lipocalin-2
  • Lipocalins
  • Macromolecular Substances
  • Oncogene Proteins
  • Proto-Oncogene Proteins
  • alpha(2)-microglobulin
  • Glycoside Hydrolases
  • glycanase
  • Collagenases
  • Matrix Metalloproteinase 9
  • Tetradecanoylphorbol Acetate

Associated data

  • GENBANK/P80188