Abstract
A modified digestion system using radiolabeled IgM rheumatoid factors (RF) and unlabeled IgG was used to examine IgM RF digestion by human polymorphonuclear leukocyte (PMN) elastase. Upon molecular sieve chromatography, the radioactive fragments coelute with fragments produced by elastase digestion of an IgM protein having no RF activity. The fragments represent an Fab2-like fragment, an Fab-like fragment, and small peptides. Utilizing this same system, digests were performed at both acid and neutral pH to compare the proteolytic action of purified elastase on IgM RF (Ove) to the action of the total granule extract (TGE) from human PMN. At pH 4.5, purified elastase exhibits low-level protease activity, producing a slightly degraded IgM fragment with a molecular weight of about 800,000 daltons. In contrast, TGE at pH 4.5 completely degrades IgM RF to small peptides. At pH 7.5, the fragments produced by TGE digestion of IgM (Ove) coelute with fragments produced by elastase digestion under the same conditions. Thus elastase appears to be the major granule protease active in IgM RF degradation at the pH characterizing the inflammatory site.
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Prince, H. E., J. D. Folds, andJ. K. Spitznagel, 1979. Interaction of human polymorphonuclear leukocyte elastase with human IgM. In vitro production of an Fabu-like fragment.Molec. Immunol. 16:301.
Prince, H. E., J. D. Folds, andJ. K. Spitznagel. 1979, In vitro production of a biologically active Fab2u-like fragment by digestion of human IgM rheumatoid factor with human polymorphonuclear leukocyte elastase.Molec. Immunol. 16:975.
Parker, R. L., andF. R. Schmid. 1962. Phagocytosis of paniculate complexes of γ-globulin and rheumatoid factor.J. Immunol. 88:519.
Folds, J. D., H. Prince, andJ. K. Spitznagel. 1978. Limited cleavage of human immunoglobulins by elastase of human neutrophil polymorphonuclear granulocytes: Possible modulator of immune complex disease.Lab. Invest. 39:313.
Morris, J. E., andF. P. Inman. 1968. Isolation of the monomeric subunit to Immunoglobulin M with its interchain disulfide bonds intact.Biochemistry 7:2851.
Marchalonis, J. J. 1969. An enzymatic methods for the trace iodination of immunoglobulin and other proteins.Biochem. J. 113:299.
Janoff, A. 1973. Purification of human granulocyte elastase by affinity chromatography.Lab. Invest. 29:458.
Ruddy, S. 1974. Synovial fluid: Mirror of the inflammatory lesion in rheumatoid arthritis.In Rheumatoid Arthritis. E. D. Harris, editor. Medcom Press, New York. 58.
Jacques, Y. V., andD. F. Bainton. 1978. Changes in the pH within the phagocytic vacooles of human neutrophils and monocytes.Lab. Invest. 38:179.
Ohlsson, K., I. Ollson, M. Delshammer, andH. Schiessler. 1976. Elastases from human and canine granulocutes. I. Some proteolytic and esterolytic properties.Hoppe-Seyler's Z. Physiol. Chem. 357:1245.
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Prince, H.E., Folds, J.D., Modrzakowski, M.C. et al. A comparative analysis of human IgM rheumatoid factor degradation by purified elastase and total granule extracts from human polymorphonuclear leukocytes. Inflammation 4, 27–35 (1980). https://doi.org/10.1007/BF00914100
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DOI: https://doi.org/10.1007/BF00914100