Ozone effects on inhibitors of human neutrophil proteinases

Journal Article · Sun Feb 15 04:00:00 EST 1987 · Arch. Biochem. Biophys.; (United States)

DOI:https://doi.org/10.1016/0003-9861(87)90647-3· OSTI ID:6693089

Smith, C E; Stack, M S; Johnson, D A

The effects of ozone on human alpha 1-proteinase inhibitor (A-1-PI), alpha 1-antichymotrypsin (A-1-Achy), bronchial leukocyte proteinase inhibitor (BLPI), and Eglin C were studied using in vitro exposures in phosphate-buffered solutions. Following ozone exposure, inhibitory activities against human neutrophil elastase (HNE) and/or cathepsin G (Cat G) were measured. Exposure of A-1-PI to 50 mol O3/mol protein resulted in a complete loss of HNE inhibitory activity, whereas A-1-Achy lost only 50% of its Cat G inhibitory activity and remained half active even after exposure to 250 mol of O3. At 40 mol O3/mol protein, BLPI lost 79% of its activity against HNE and 87% of its Cat G inhibitory activity. Eglin C, a leech-derived inhibitor, lost 81% of its HNE inhibitory activity and 92% of its ability to inhibit Cat G when exposed to 40 mol O3/mol. Amino acid analyses of ozone-exposed inhibitors showed destruction of Trp, Met, Tyr, and His with as little as 10 mol O3/mol protein, and higher levels of O3 resulted in more extensive oxidation of susceptible residues. The variable ozone susceptibility of the different amino acid residues in the four proteins indicated that oxidation was a function of protein structure, as well as the inherent susceptibility of particular amino acids. Exposure of A-1-PI and BLPI in the presence of the antioxidants, Trolox C (water soluble vitamin E) and ascorbic acid (vitamin C), showed that antioxidant vitamins may protect proteins from oxidative inactivation by ozone. Methionine-specific modification of BLPI reduced its HNE and Cat G inhibitory activities. Two moles of N-chlorosuccinimide per mole of BLPI methionine caused an 80% reduction in activity against Cat G, but only a 40% reduction in HNE inhibitory activity.

• Research Organization: East Tennessee State Univ., Johnson City
• OSTI ID: 6693089
• Journal Information: Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 1; ISSN ABBIA
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
ASCORBIC ACID
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
ENZYME INHIBITORS
ENZYMES
HYDROLASES
INACTIVATION
LEUKOCYTES
MATERIALS
NEUTROPHILS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OZONE
PEPTIDE HYDROLASES
VITAMINS