Characterization of neutrophil alkaline phosphatase-inducing factor (NAP-IF)

✍ Scribed by Noriharu Sato; Shigetaka Asano; Mayumi Mori; Yoshito Ueyama; Kentaro Sugano; Nakaaki Ohsawa; Fumimaro Takaku

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 566 KB
• Volume: 124
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1041240213

✦ Synopsis

Abstract

A factor, termed neutrophil alkaline phosphatase‐inducing factor (NAP‐IF), that has the capacity to increase the NAP activity of granulocytes was characterized by using two samples: cystic fluid (CF) and conditioned medium of a tumor cell line (T3M5). The molecular weight of NAP‐IF was shown to be between 13,000 and 45,000, and its isoelectric point was between 5.5 and 6.2. It was sensitive to heat and proteolytic enzymes, but was resistant to DNase and RNase, suggesting that NAP‐IF is an acidic protein or glycoprotein. These characteristics of NAP‐IF seem to be similar to those of granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) that is also present in the CF. NAP‐IF rich fractions obtained by isoelectric focusing from CF were also found to be rich in a subclass of GM‐CSF: granulocyte‐CSF (G‐CSF). Furthermore, a high correlation was noted between the activities of G‐CSF and NAP‐IF (γ = 0.798, P < 0.005). These results suggest that the two activities, i.e., G‐CSF and NAP‐IF, may be attributable to an identical macromolecule.