Opsonic antibodies evoked by hybrid peptide copies of types 5 and 24 streptococcal M proteins synthesized in tandem

The protective immunogenicity of a hybrid peptide containing tandem copies of types 5 and 24 epitopes was investigated. Carboxy-terminal peptides of the cyanogen bromide-derived fragment 7 (CB7) of type 24 M protein were chemically synthesized, and then extended to include the first 20 residues of the amino-terminus of type 5 M protein. When emulsified in CFA and injected into rabbits without conjugation to a carrier, each of the synthetic hybrid peptides, designated S-M5(1-20)-S-CB7(23-35)C and S-M5(1-20)-S-CB(19-34), evoked opsonic antibodies against both types 5 and 24 streptococci without raising heart tissue-crossreactive immunity. These results suggest that tandem hybrid peptides may provide a new approach to the development of multivalent vaccines, not only to different serotypes of group A streptococci but perhaps also to a variety of other infectious agents.

Epitope-specific protective immunogenicity of chemically synthesized 13-, 18-, and 23-residue peptide fragments of streptococcal M protein

The ability of chemically synthesized subpeptides of type 24 streptococcal M protein to evoke protective antibodies in rabbits was investigated. We synthesized copies of the COOH-terminal 13, 18, and 23 amino acid residues of cyanogen bromide fragment 7 (CB7) of pepsin-extracted type 24 M protein, except that methionine was substituted for homoserine as the COOH-terminal residue. An additional residue of cysteine was added at the COOH terminus of the 13-residue peptide. Each of the peptides, designated S-CB7-(23-35)-Cys, S-CB7-(18-35), and S-CB7-(13-35), when conjugated to lysylated tetanus toxoid with glutaraldehyde, was capable of stimulating formation of protective anti-type 24 M protein antibodies in rabbits. The smallest peptide, S-CB7-(23-35)-Cys, elicited immune responses equally as strong, if not stronger, than those to the longer peptides. A single Lys/Gly substitution in this 13-residue peptide resulted in its failure to stimulate protective antibodies. None of the antisera reacted with heterologous serotypes of M protein and none reacted with frozen sections of human heart tissue. These results indicate that a chemically synthesized peptide fragment corresponding to as few as 13 amino acid residues of streptococcal M protein is capable of evoking protective anti-streptococcal antibodies without evoking antibodies crossreactive with cardiac tissue.

Isolation of cDNA clones and genomic DNA clones of beta-subunit of chicken prolyl 4-hydroxylase

Prolyl 4-hydroxylase (EC 1.14.11.2) is a key enzyme in collagen biosynthesis. The active enzyme is a tetramer composed of two pairs of non-identical subunits, alpha and beta. Sheep antiserum directed against chicken proly 4-hydroxylase was initially used to screen two cDNA expression libraries. The cDNA was prepared from chicken smooth muscle mRNA and cloned into the plasmids pUC8- and pUC9. Antibodies identified twenty-five clones among the approximately 2 x 10(5) clones in the libraries. Ten clones were isolated pure and used in the subsequent analysis. Monospecific antibodies directed against beta subunit of the enzyme were used in Western-blot analyses of extracts of bacteria carrying the cDNA clones. The results indicated that the clone CPH 9-10B encodes a portion of beta-subunit. The cDNA from CPH 9-10B was used to screen another cDNA library prepared from mRNA from chicken skeletal muscle. Several overlapping clones were isolated. Together the cDNAs correspond to 2.4 kb which is the same as the corresponding mRNA. Three regions of the amino acid sequence deduced from the cDNA sequence matched with that of the NH2-terminus of beta-subunit and two CNBr peptides derived from beta-subunit. The cDNA of CPH 9-10B was also used to screen a genomic DNA library constructed with lambda EMBL-3. Two overlapping genomic clones lambda gCPH beta-22 and beta-50 were isolated and characterized by restriction enzyme analysis. The results indicate that lambda gCPH beta-22 contains the portion of the beta-subunit gene that is transcribed into the 5' portion of beta-subunit mRNA, whereas lambda gCPH beta-50 contains the 3' portion.

Covalent structure of collagen: amino acid sequence of alpha 1 (III)-CB5 from type III collagen of human liver

Type III collagen was prepared from human liver by limited pepsin digestion, differential salt precipitation, and carboxymethylcellulose chromatography. Ten distinct peptides were obtained by cyanogen bromide digestion. The peptide alpha 1 (III)-CB5 was further purified by carboxymethylcellulose chromatography, and its amino acid sequence was determined. Automatic Edman degradation of intact alpha 1 (III)-CB5, tryptic and thermolytic peptides, and hydroxylamine-derived fragments was used to establish the total sequence. The mammalian collagenase site contained in the alpha 1 (III)-CB5 sequence was ascertained by digestion of native type III collagen with purified rheumatoid synovial collagenase. Collagenase cleavage occurred at a single Gly--Ile bond, one triplet before the corresponding specific cleavage site of type I collagen. The present work brings the known sequence of human liver type III collagen to include alpha 1 (III)-CB3-7-6-1-8-10-2-4-5. These correspond to the homologous region of alpha 1 (I)-CB0-1-2-4-5-8-3-7 residues 11--804.

Isolation, characterization and partial amino acid sequence of a phosphorylated polypeptide (E4) from bovine embryonic dental enamel

A phosphorylated polypeptide (E4) of molecular weight 5000-6000, has been isolated from bovine embryonic enamel by Bio-Gel P-10 gel filtration and DE-52 ion-exchange chromatography. The peptide contains three serine residues all of which are phosphorylated. All three O-phosphoserine residues are in glutamic acid-O-phosphoserine-tyrosine sequences that are distributed relatively evenly along the polypeptide chain. Although it was not possible to sequence the entire polypeptide chain directly by automatic peptide sequencing, a partial sequence and peptide map was constructed on the basis of the sequence and composition of peptides derived by cyanogen bromide, trypsin and chymotrypsin digestion. The presence of glutamic acid, tyrosine and leucine adjacent to and near the O-phosphoserine residues may be important in calcium binding and in mineralization.

Noncollagenous nature of the proteins of shark enamel

The proteins, soluble and insoluble at neutral pH, of relatively mature enamel of two different species of sharks were distinctly different from both collagen and embryonic enamel proteins and similar to the proteins isolated from mature human and bovine enamel.

Covalent structure of collagen. Amino acid sequence of an arthritogenic cyanogen bromide peptide from type II collagen of bovine cartilage

Bovine articular type II collagen was prepared by limited pepsin digestion, differential salt fractionation and carboxymethylcellulose chromatography. Cyanogen bromide digestion of purified type II collagen alpha chains yielded twelve distinct peptides designated CB1-12. The peptide alpha 1(II)-CB11 was isolated by carboxymethylcellulose chromatography and Sephadex G-75S gel filtration. Automated Edman degradation together with chymotrypsin, thermolysin and trypsin digestion enabled identification of its complete amino acid sequence. Compared with type I and type III collagen, the data show similarity with alpha 1(I)-CB8 and alpha 1(III)-CB6-1-8-10-2 peptides, respectively. The peptide is located within residues 124-402 of the alpha 1(II) collagen chain and with its identification, now extends the known amino acid sequence of bovine type II cartilage collagen to 660 amino acid residues including alpha 1(II)-CB1-2-6-12-11-8-10 (partial). This corresponds to alpha 1(I)-CB0-1-2-4-5-8-3-7 (partial; 1-660) and alpha 1(III)-CB3A-3B-3C-7-6-1-8-10-2-4-5 (partial; 1-660) of bovine alpha 1(I) and alpha 1(III) collagen chains.

Type IV collagens' isolation and characterization of 7S collagen from human kidney, liver and lung

7S collagens were isolated after bacterial collagenase treatment of basement membrane material prepared from the pepsin digest of human kidney, liver and lung. The 7S collagens were purified by combination of molecular sieve and ion exchange chromatography. 7S collagen from each of these sources showed similar amino acid composition, electrophoretic patterns of reduced and unreduced samples. Antibodies raised against human placental 7S collagen in rabbits completely cross-reacted with the 7S collagen preparation obtained from kidney, liver and lung in enzyme-immunoassays. Since 7S collagen in known to be a major cross-linked segment of type IV collagens, the data indicate that collagenous proteins of basement membranes are organized in similar networks in a variety of organs.

Kupffer cells from carbon tetrachloride-injured rat livers produce chemotactic factors for fibroblasts and monocytes: the role of tumor necrosis factor-alpha

Conditioned media from cultured Kupffer and mononuclear macrophagic cells obtained 48 hr after CCl4 administration to rats contains chemotactic factors for human skin fibroblasts and human monocytes. The chemotactic mediator for fibroblasts was approximately 17 kD and was more prominent at early stages of culture. It induced a dose-dependent chemotactic response in fibroblasts. Although the conditioned medium from cultured Kupffer cells of normal rats also contained detectable biological activity, it was significantly less than that in conditioned medium from cultured Kupffer cells from CCl4-treated rats. The activity obtained after purification by high-performance liquid chromatography was completely ablated by incubation with tumor necrosis factor-alpha antibody. Transforming growth factor-beta antibody diminished biological activity by 20%. Human recombinant tumor necrosis factor-alpha and transforming growth factor-beta used in the assay as control showed significant chemotactic activity. The chemotactic activity present in whole normal conditioned medium was only present after 24 and 48 hr of culture. Furthermore, this activity was not neutralized by human recombinant tumor necrosis factor-alpha or transforming growth factor-beta antibodies. Incubation of whole 6-hr conditioned medium with human recombinant tumor necrosis factor-alpha and transforming growth factor-beta antibodies demonstrated and confirmed that tumor necrosis factor-alpha plays a major role in inducing the chemotactic response. On acidification of this supernatant, we found a notable increase in the biological response that could be neutralized by transforming growth factor-beta antibody. Thus tumor necrosis factor-alpha and transforming growth factor-beta may sequentially provide important signals for fibroblast and monocyte recruitment in vivo at initial stages of liver injury.

Vimentin-cross-reactive epitope of type 12 streptococcal M protein

The NH2-terminal amino acid sequence of type 12 M protein was determined by automated Edman degradation of a 38-kilodalton polypeptide fragment purified from a limited pepsin digest of intact type 12 streptococci. The sequence of the first 13 amino acid residues of the polypeptide confirmed that predicted by the nucleotide sequence of the mature type 12 M protein. A chemically synthesized peptide copying the NH2-terminal 25 residues, SM12(1-25)C, evoked opsonic antibodies against type 12 streptococci as well as renal glomerular cross-reactive antibodies. The serum from one of six rabbits reacted in immunofluorescence tests with human glomeruli in a mesangial staining pattern. The cross-reactive antibodies were completely inhibited by the immunizing peptide and absorption with type 12 streptococci. Subpeptides of the 25-residue synthetic peptide were without inhibitory effect, suggesting that the cross-reactive antibodies are directed against a conformational epitope of SM12(1-25)C. Anti-SM12(1-25)C antisera reacted specifically with the intermediate filament protein vimentin extracted from mesangial cells. None of the cross-reactions of anti-SM12(1-25)C were inhibited by a synthetic peptide SM1(1-26)C of type 1 M protein, which was previously shown to share a cross-reactive epitope with vimentin. These results indicate that type 12 M protein contains at least one vimentin cross-reactive epitope that is clearly distinct from the tetrapeptide epitope shared with vimentin by type 1 M protein.

Covalent structure of collagen: amino acid sequence of alpha 2-CB5 of chick skin collagen containing the animal collagenase cleavage site

The amino acid sequence of the 112 residues from the amino terminus of alpha 2-CB5 from chick skin collagen was determined by automated sequential degradation of intact alpha 2-CB5 and several chymotryptic and tryptic peptides. This segment of the peptide includes the site of the action of animal collagenases. As compared to the sequence around the alpha 1 cleavage site, the alpha 2 sequence is notable for the remarkable constancy of the residues to the amino side and the relative abundance of hydrophobic residues to the carboxyl side of the cleavage site, suggesting that these features are important in the recognition by the enzyme. The sequence of this region of the alpha 2 chain is consistent with the Gly-X-Y triplet structure and the preference of certain residues for either the X or Y position in distribution. However, three of the six residues of leucine were found in the Y position rather than the X position. Leucine residues were found only once in the Y position in the alpha 1 (I) chain. This preference does not appear to hold in the alpha 2 chain.

Investigation of type I and type III collagens of the lung in progressive systemic sclerosis

The interstitial collagens, type I and type III, were investigated in lung tissue from patients with progressive systemic sclerosis (PSS) with pulmonary involvement. By use of CNBr digestion of whole tissue, the relative content of type I versus type III collagen was unchanged. This contrasts with idiopathic pulmonary fibrosis. Limited pepsin digestion released greater amounts of collagen (55%) than normal (16%), but the individual collagen chains were chemically indistinguishable. A reduced amount of the more stable collagen crosslink, hydroxylysinonorleucine, was observed which was consistent with the relatively greater degree of solubilization.

Collagen-platelet interaction: separate receptor sites for types I and III collagen

We have isolated a platelet membrane protein of M(r) 47 kDa which is responsible for the interaction of platelets with type III collagen. The 47 kDa protein was purified to apparent homogeneity by type III collagen-Sepharose 2B column chromatography and preparative slab gel electrophoreses. The 47 kDa protein blocked the adhesion of platelets to type III but not to type I collagen. Polyclonal antibodies were obtained from rabbits immunized with the purified 47 kDa protein emulsified in complete Freund's adjuvant. The polyclonal antibodies inhibited the type III collagen but not type I collagen-induced platelet aggregation. The inhibitory effect of the antibodies on type III collagen-induced platelet aggregation was dose-dependent. Cross-inhibition on platelet aggregation studies showed that type I collagen receptor antibodies (M(r) 65 kDa) did not inhibit type III collagen-induced platelet aggregation and type III collagen receptor antibodies did not inhibit type I collagen induced platelet aggregation. These results suggest that type I and type III collagens interact with platelets at separate sites.

Interleukin 1 alpha and an interleukin 1 beta fragment are somnogenic

The somnogenic activity of interleukin 1 beta (IL-1 beta) has previously been established. Interleukin 1 alpha (IL-1 alpha) is a distinct gene product that possesses similar biological activities. We report here that IL-1 alpha, like IL-1 beta, has the capacity in rabbits to enhance non-rapid-eye-movement sleep, electroencephalographic slow-wave (0.5-3.5 Hz) voltages, and body temperatures and to inhibit rapid-eye-movement sleep. After IL-1 alpha, sleep remained episodic, and at the doses used no abnormal behavior was observed. Several synthetic IL-1 alpha and IL-1 beta peptides were also tested in vivo for somnogenic and pyrogenic activity and in vitro for their ability to stimulate prostaglandin E2 (PGE2) production by fibroblasts and proliferation of T-cells. Only IL-1 beta-(208-240) enhanced non-rapid-eye-movement sleep and body temperature, although both IL-1 beta-(208-240) and IL-1 alpha-(223-250) stimulated PGE2 production; both of these peptides failed to stimulate T-cell production. In contrast, four other IL-1 peptides were nonpyrogenic and somnogenically inactive yet stimulated T-cell proliferation. We conclude that the components of IL-1 required for sleep and temperature activities are different from those required for T-cell proliferation.

Intracellular phosphorylation of the Sendai virus P protein

Phosphorylation status of the Sendai virus P protein was examined during virus infection and compared with cell-free phosphorylation. P protein from Sendai virus-infected (VI) and P/C gene-transfected (PT) mammalian cells and from purified virions (PV) was phosphorylated at only serine residues. In contrast, cell-free phosphorylation of the P protein with virion-associated protein kinase (VAPK) occurred at both threonine and serine. Tryptic phosphopeptide maps of the P protein from VI, PT, and PV showed that the phosphorylation was primarily localized on one peptide (TP1), while VAPK phosphorylated the P protein on several peptides. There was no change in the steady-state phosphopeptide map of the P protein during virus replication, indicating that the TP1 is constitutively phosphorylated. Inhibition of cellular phosphatases (PP1 and PP2A) by okadaic acid (OA) in virus-infected cells caused a sixfold increase in the P protein phosphorylation, solely at serine residues. The phosphopeptide map of the OA-P protein revealed that phosphorylation occurred on several peptides, but the OA-P map was significantly different from the VAPK-P map. However, additional phosphorylation of the P protein did not block its association with nucleocapsids. These results suggest that the Sendai virus P protein is constitutively phosphorylated primarily at one locus but has the potential for phosphorylation at additional sites. Further, our results do not show any correlations between the intracellular and cell-free phosphorylation of the P protein and, therefore, question the validity of cell-free phosphorylations.