SP-A binds alpha1-antitrypsin in vitro and reduces the association rate constant for neutrophil elastase.

ABSTRACT:

Background

Alpha1-antitrypsin and surfactant protein-A (SP-A) are major lung defense proteins. With the hypothesis that SP-A could bind alpha1-antitrypsin, we designed a series of in vitro experiments aimed at investigating the nature and consequences of such an interaction.

Methods and results

At an alpha1-antitrypsin:SP-A molar ratio of 1:1, the interaction resulted in a calcium-dependent decrease of 84.6% in the association rate constant of alpha1-antitrypsin for neutrophil elastase. The findings were similar when SP-A was coupled with the Z variant of alpha1-antitrypsin. The carbohydrate recognition domain of SP-A appeared to be a major determinant of the interaction, by recognizing alpha1-antitrypsin carbohydrate chains. However, binding of SP-A carbohydrate chains to t

SUBMITTER: Gorrini M 

PROVIDER: S-EPMC1343571 | biostudies-literature | 2005 Dec

REPOSITORIES: biostudies-literature