Kueppers, Friedrich

Abstract The granulocyte lysosomal elastase of 17 patients with chronic obstructive pulmonary disease and of 27 normal subjects was examined. Serum a 1-antitrypsin phenotypes were identical in the 2 groups: 88 per cent were type PiM and 12 per cent were type PiMS. Electrophoresis of granulocyte lysosomal extracts at pH 8.6 revealed interindividual differences in the electrophoretic mobility of the elastase enzyme. The elastases clustered into 3 regions of electrophoretic mobility, which we designated as fast (>29 mm), intermediate (24 through 29 mm), and slow (<24 mm) migration. A comparison of the number of patients and normal subjects in each electrophoretic category showed an almost 4-fold increase in the prevalence of the slow electrophoretic type of elastase in the patient group compared to the normal subjects. Esterase activity in lysosomal extracts against the synthetic elastase substrate N-t-BOC-L-alanine-p-nitrophenyl ester (NBA) varied within a 4 to 5-fold range in both patient and normal populations. No significant differences in the mean esterase activities between the patient group and the normal group could be detected within each elastase category (slow, intermediate, or fast mobility). The mean elastase NBA esterase activity was lowest in the slow elastase electrophoretic category and highest in the fast elastase type. Mean esterase activity in the intermediate electrophoretic category was intermediate between those of the slow and the fast electrophoretic types of elastase. The increase in the number of patients in the slow electrophoretic category with lowest mean elastase esterase activity suggests that qualitative rather than quantitative aspects of elastase may be critical in the pathogenesis of chronic obstructive pulmonary disease in patients with normal a 1-antitrypsin phenotypes.

Guinea pig eosinophil granules are characterized by the presence of a basic protein of low molecular weight which accounts for greater than 50% of granule protein. This protein, termed the major basic protein (MBP), readily aggregates and becomes insoluble, and the formation of aggregates is dependent on the establishment of disulfide bonds. Analysis of concentrated preparations of MBP often revealed a series of bands which were multiples of a monomeric unit with a mol wt of approximately 11,000. Analysis of reduced and alkylated MBP on a 10% agarose column equilibrated with 6 M guanidinium chloride revealed a single polypeptide chain with a mol wt of 10,800. Amino acid analysis of the protein revealed the presence of 13% arginine, consistent with the basic character of the molecule. Four residues of tryptophan, were present, indicating that MBP is not a histone. The MBP did not increase vascular permeability when injected into the skin of guinea pigs, nor did it antagonize the effect of histamine and bradykinin in the skin. MBP also did not contract the isolated guinea pig ileum and when mixed with histamine or bradykinin did not inhibit their activity on the gut. MBP had only weak, if any, antihistaminic activity. MBP possessed weak bactericidal activity when compared to histone and then only with one strain of E. coli. MBP precipitated DNA, neutralized heparin, and activated papain. On a molar basis MBP was more active than cysteine in activating papain. These results do not point to any unique biological activity associated with MBP other than those expected of a protein as basic as it is and one which possesses reactive sulfhydryl groups. Possible functions of eosinophils based on the properties of the MBP are discussed.