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Biomedical subjects

E F Osserman

Publications and source records attributed to E F Osserman.

15 recordsLinked to original sources

Amino acid sequence of the FV region of a human monoclonal IgM (NOV) with specificity for the capsular polysaccharide of the group B meningococcus and of Escherichia coli K1, which cross-reacts with polynucleotides and with denatured DNA.

The complete amino acid sequences of the VH and VL regions of a biologically significant Ig, IgMNOV, were determined. IgMNOV is reactive with the capsular polysaccharide of the group B meningococcus and of Escherichia coli K1. As reported earlier, it cross-reacts completely with polynucleotides poly(A) and poly(I) and to a lesser extent with denatured DNA and protects newborn rats against infection with E. coli K1, and is equal in potency to the standard horse anti-group B meningococcal serum. The reduced and alkylated chains were sequenced directly, identifying the L chain as lambda-subgroup II and the mu-H chain as subgroup III. The complete sequence of the VL region was determined by sequencing peptides generated by cleavage with Staphylococcus aureus protease, chymotrypsin, and trypsin. The H chain was cleaved with cyanogen bromide followed by enzymatic cleavages to obtain a large part of the VH region sequence. The structure was completed by sequencing tryptic peptides of the Fab fragment and by mass-spectrometric analysis.

Amino Acid Sequence

The second riboflavin-binding myeloma IgG lambdaDOT. I. Biochemical and functional characterization.

A human monoclonal immunoglobulin, IgGDOT, with flavin-binding capacity has been obtained from an elderly woman with multiple myeloma who developed yellow skin and yellow hair. The case presented a remarkable similarity with that previously reported by Farhangi and Osserman [N. Engl. J. Med. 294, 177-183 (1976)]. Purified IgGDOT was bright yellow and the ligand was identified as riboflavin and its oxidation products by thin layer chromatography, proton nuclear magnetic resonance and mass spectroscopy. Competitive binding studies with different haptens demonstrated highest affinity for riboflavin, followed by flavin mononucleotide and flavin adenine dinucleotide; no significant binding was detected for several other non-flavin compounds tested. The hapten was associated with the protein in vivo, as well as with the purified antibody. Removal of the already bound riboflavin from the combining site was associated with irreversible denaturation of the monoclonal protein. By the fluorescence quenching technique it was determined that there were 0.68 available combining sites for riboflavin molecule in IgGDOT with a binding constant of 8.5 x 10(8)/M, while FabDOT presented 0.27 available combining sites with a binding constant of 5.1 x 10(8)/M. The fact that 1.2 and 0.81 mol riboflavin/mol protein were already bound to IgGDOT and FabDOT, respectively, is consistent with the usual hapten/antibody stoichiometry. The heavy chain subclass of IgGDOT was identified as gamma 2, as in the previously reported case of riboflavin-binding protein IgGGAR. However, the lambda chain subclass was different and no idiotype cross-reactivity was found.

Aged

The epitope associated with the binding of the capsular polysaccharide of the group B meningococcus and of Escherichia coli K1 to a human monoclonal macroglobulin, IgMNOV.

The fine structure of the combining site of human mAb IgMNOV to poly-alpha(2----8)linked NeuNAc, the epitope of the group B meningococcal and E. coli K1 polysaccharides, has been probed using RIA and ELISA. Inhibition by oligomers ranging from 2 to 12 residues was used to assay binding to IgMNOV by group B meningococcal polysaccharide preparations (GBMP) or by poly(A). The inhibitory properties of the oligomers were almost identical in both assays of the binding of GBMP to horse IgM (H46). This evidence and the finding that both GBMP and poly(A) precipitated IgMNOV equally per unit weight indicated that the epitope of poly(A) must mimic an equivalent epitope on GBMP despite the absence of any apparent common structural features in the two molecules. Unlike most carbohydrate-anticarbohydrate systems in which the site is saturated by oligomers of up to six or seven sugars, all the anti-alpha(2----8)NeuNAc systems above required much larger oligomers. Because these oligomers are larger than the maximum size of an antibody site the epitope must be conformationally controlled, and this has been confirmed by nuclear magnetic resonance spectroscopy. However, despite the above similarities, GBMP and poly(A) were differentiated in that only GBMP bound to H46. Smaller linear molecules obtained by delipidating the GBMP, as well as periodate-oxidized GBMP with its nonreducing end oxidized or linked covalently to BSA, bound to and precipitated IgMNOV and H46. This showed that, despite their differences, terminal nonreducing ends were not involved and that both epitopes were located in the conformationally controlled inner residues of the GBMP. The difference thus must reside in the ability of IgMNOV and H46 to recognize different structural aspects of the same conformationally controlled inner residues. The ELISA data indicate that both IgMNOV and H46 have groove-type sites that bind exclusively to an epitope located on the acidic side of the inner residues. The differences determining the ability of IgMNOV and the failure of H46 to cross-react with poly(A), poly(I), and denatured DNA, may depend on differences in the degree of protonation required by each antibody, and this may be clarified by a study of the effects of pH on the precipitin behavior of IgMNOV and H46.

Antibodies, Monoclonal

Modulation of neutrophil function by lysozyme. Potential negative feedback system of inflammation.

Host responses to infectious organisms should be modulated so that tissue-damaging products of inflammatory cells do not produce excessive destruction of normal tissue. Lysozyme, which is continuously secreted by monocytes, which, in turn, migrate relatively late to inflammatory areas, was found to significantly dampen several responses of neutrophils to inflammatory stimulants. Thus, human lysozyme obtained and purified from the urine of patients with monocytic leukemia (but not its structurally similar and comparably cationic analogue, eggwhite lysozyme) depresses chemotaxis of normal neutrophils to activated complement, bacterial supernate, and N-formylmethionyl-phenylalanine. In addition, human (but not eggwhite) lysozyme depresses oxidative metabolism (hexose monophosphate shunt activity) and superoxide generation of neutrophils. The specificity of the suppressive effects was indicated by inhibition studies with rabbit antihuman lysozyme antibody, and with the trisaccharide of N-acetylglucosamine, a specific inhibitor of lysozyme. The results suggest that lysozyme, a product of inflammatory cells themselves, may function in a negative feedback system to modulate the inflammatory response.

Cell Migration Inhibition

Computer-based case tracing (COMTRAC).

To assist clinical assessment and decision making, a computer-based system has been developed to organize key data of individual medical records and display these data in a standard graphic format for each disease. A program for multiple myeloma has been completed and 150 case records entered. The data accessed by computer-based case tracing on all cases of a particular disease are available for cumulative and comparative analyses of different therapeutic regimens.

Data Display

Serum lysozyme, serum proteins, and immunoglobulin determinations in nonspecific inflammatory bowel disease.

The serum levels of lysozyme, serum electrophoresis, and serum immunoglobulins were determined prospectively in 101 patients with ulcerative colitis, ulcerative proctitis, Crohn's disease, or nonclassifiable nonspecific inflammatory bowel disease. Although the mean serum lysozyme concentration of patients with Crohn's disease (10.5 +/- 6.8 microgram/ml) and ulcerative colitis (9.6 +/- 4.1 microgram/ml) performed by a standardized lysoplate method was significantly greater than normal controls (6.0 +/- 1.5 microgram/ml), the results did not correlate with the diagnosis nor with the degree of disease activity. Individually separated protein fractions and serum immunoglobulins also did not correlate with the serum lysozyme levels. This study indicates that measurement of the level of serum lysozyme in individual patients is not helpful in determining the cause or degree of activity of nonspecific inflammatory bowel disease.

Adult

Primary structure of rat lysozyme.

For evolutionary reasons, we determined the primary structure of rat lysozyme. The chymotryptic peptides from the reduced and carboxymethylated protein were sequenced and aligned by homology with the sequence of human lysozyme. Overlaps were confirmed by partial structures of tryptic peptides and an automatic sequencer run on the whole protein. By comparing this lysozyme sequence with those of human and baboon and taking into account paleontological estimates of the times of divergence of these species from one another, an approximate estimate of the average rate of lysozyme evolution was made. This rate is not significantly different from the average rate of lactalbumin evolution in mammals--a finding which is at variance with Dickerson's [Dickerson, R.E. (1971), J. Mol. Evol. 1, 26] and Dayhoff's [Dayhoff, m.o., ed. (1972), Atlas of Protein Structure and Sequence, Vol. 5, Silver Spring, Md., The National Biomedical Research Foundation] conclusion that lactalbumin evolution has been faster than lysozyme evolution. Our finding raises the possibility that the gene duplication event responsible for the origin of lactalbumin from lysozyme was more ancient than is generally supposed. Furthermore, from comparison of the rates of lysozyme evolution in rodents and primates, it is suggested that generation time is not a key factor in lysozyme evolution.

Amino Acid Sequence

Myeloma with xanthoderma due to an IgG lambdamonoclonal anti-flavin antibody.

When yellow skin and yellow hair developed in an elderly patient with multiple myeloma, we ruled out the usual causes of such pigmentation but identified a monoclonal IgGlambda (lgGGar) with anti-flavin antibody activity. Purified IgGGar was bright yellow, and the acid-dissociated chromophore was identified as riboflavin by chromatography and absorption spectroscopy. Native IgGGar contained 1.45 moles of flavin per mole of IgG, and increased to 2 moles with addition of riboflavin to saturation. The flavin was localized to the Fab fragment and was bound to IgGGar with high affinity. IgGGar showed strongest affinities for riboflavin, flavin mononucleotide and flavin adenine dinucleotide, and lower affinities for dinitrophenyl derivatives and naphthoquinone. The demonstration of hapten bound to the circulating monoclonal immunoglobulin in this case suggests the possibility of bound but colorless haptens on other myeloma proteins as well as on normal immunoglobulins.

Aged

Experimental Bence Jones cast nephropathy.

C3H mice received intraperitoneal injections of a single dose of 50 to 200 mg. of purified lambda Bence Jones protein. Control animals received injections of comparable amounts of ovalbumin. The mice which received 200 mg. of lambda Bence Jones protein developed extensive cast formation in the distal renal tubules. By electron microscopy, the casts were found to contain elongated crystalloid structures. In some areas, these crystalloids appeared to penetrate into or be engulfed by tubular epithelial cells. By immunofluorescence, only lambda Bence Jones protein was detectable in the casts during the first 5 days. Thereafter, Tamm-Horsfall protein was also found in increasing amounts. The casts induced an inflammatory response characterized by the sequential appearance of polymorphonuclear leukocytes and mononuclear cells. The secondary tubular cell changes included atrophy, degeneration, and regeneration. Giant cells were present around many casts, but it could not be determined whether these derived from tubular epithelial or mononuclear inflammatory cells. Elevated blood urea nitrogen was found terminally in most animals. Smaller doses of the same protein as well as preliminary studies with two other lambda Bence Jones proteins failed to produce comparable changes. This experimental model of Bence Jones nephropathy closely resembles the morphologic features of so-called "myeloma kidney" in man.

Animals

IgA heavy chain disease. A case detected in the western hemisphere.

IgA heavy chain disease (alpha chain disease) was detected in a 46 year old South American (Colombian) of mixed Spanish and Indian (Mestizo) descent. The clinical course was characterized by severe malabsorption, initially thought to be a variant of tropical sprue. Jejunal mucosal biopsy revealed marked villous atrophy with heavy infiltration of the lamina propria by a single monotonous cell type which, by light microscopy, had the appearance of either a large, abnormal plasma cell or a small histiocyte. Electron microscopy of the biopsy specimen demonstrated the presence of abnormal plasma cells, lymphatic distention and abnormalities of surface epithelial cells. At autopsy a 6 by 3 cm mass was found in the right para-aortic area along with many firm 2 cm mesenteric and para-aortic lymph nodes. Histologic examination revealed the presence of a monotonous cell type similar to that found in the jejunal mucosal biopsy specimen.

Abdomen

Primary structure of a deleted human lambda type immunoglobulin light chain containing carbohydrate: protein Sm lambda.

An internal molecular deletion occurring in a human lambda type immunoglobulin light (L)-chain (Sm lambda) has been defined by sequence analysis. The Sm protein was isolated from the urine of a patient with a plasma cell dyscrasia involving the synthesis of an IgG molecule with both deleted gamma and lambda subunits. The Sm lambda polypeptide chain has an approximate molecular weight of 15,000 and contains 135 amino-acid residues. The constant (C) region is fully intact, comprising 105 residues, whereas the variable region (V) has only 30 residues. The V-region segment represents residues 1 through 30 of normal lambda chains and possesses considerable homology (87%) to lambda chains of subgroup II. Since lambdaII proteins normally contain 216 amino-acid residues, the defect represents an intramolecular deletion of 81 residues, which is entirely confined to the carboxyterminal three-quarters segment of the V-region, with a resumption of normal synthesis at a glutaminyl residue at position 110, the initiation point of the C-region. Carbohydrate is attached to an Asx residue at position 25, in the first hypervariable region, associated with the sequence triplet Asx-Ser-Ser, which is postulated to be a common recognition site for glycosylation of immunoglobulins. The carbohydrate moiety is a complex oligosaccharide with a branched chain structure containing sialic acid, fucose, mannose, N-acetylglucosamine, and galactose. These structural studies and other findings suggest that restricted areas in the DNA of immunoglobulin genes, such as the hinge regions of heavy (H) and light (L) chains and the hypervariable regions, are particularly susceptible to breakage and reunion. We postulate that the genetic defect of protein Sm could have originated from a somatic mutational event in the plasmacyte precursor during or after the integration of the V and C genes. These studies provide additional support for the hypothesis and two distinct structural genes encode a single immunoglobulin polypeptide chain.

Amino Acid Sequence

Human lysozyme (origin and distribution in health and disease).

Histochemical and in particular immunoperoxidase techniques have extended our knowledge about the cellular distribution of LZM. The enzyme has been detected in: 1. granulocytes, which synthesize LZM in bone marrow; 2. cells of the mononuclear phagocytic system, which synthesize LZM continuously; 3. various exocrine glands, whose LZM is probably in part synthesized locally and in part derived from blood; 4. cartilage, which probably synthesizes LZM and 5. the kidney, in which LZM is serum-derived. In pathological conditions, such as inflammation and neoplasia, most LZM-positive cells at the site of disease are either granulocytes or members of the mono-nuclear phagocytic system. A notable exception are the metaplastic Paneth cells that occur along the gastrointestinal tract in inflammation and neoplasia. LZM is an antibacterial agent, but evidence is accumulating which suggests that the enzyme might have other functions as well.

Animals