Title : Isolation and primary structure of
NGAL , a novel
protein associated with human
neutrophil gelatinase
Abstract :
- 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