Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have determined the variable region sequences of four heavy chains from beta(1-6)D-galactan-binding myeloma proteins. Two of these proteins are identical to position 100 which is located in the third complementarity-determining region (CDR-3). The remaining two differ at a total of 8 positions over the first 100 amino acids, and all of the differences can be explained by single-base mutations at the DNA level. When an assessment is made of the protein segment following CDR-3, which has been termed "J segment" or "FR4," a completely different pattern of variation is observed. The J segments from the four proteins can be divided into two sets. Members of each set share a series of linked amino acids not found in members of the alternative set. The two proteins identical to position 100 have J segments from the two different sets, suggesting that recombination has occurred between V and J genes. An examination of the CDR-3 sequences from the four heavy chains reveals substitutions at positions 100 and 105. Gly is found at 100 in two of the proteins and His in the remaining two. In the two proteins with Gly-100, the following J sequence is limited to one of the two sets of J segments defined by linked amino acids. Similarly, the two heavy chains with His-100 have J segments from the second set. Thus, at the protein level an apparent association is seen between CDR-3 and J segment. If CDR-3 should be found linked to J segment at the DNA level, a new mechanism would be introduced for increasing antibody diversity by recombining various CDR-3 plus J genes with genes coding for the remainder of the variable region. Alternatively, if CDR-3 were coded for by the V gene, then the recombination of V with J may provide an opportunity to introduce mutations in CDR-3. In this case the linkage of amino acids in CDR-3 and the J segments would suggest that recognition signals are used such that certain V genes only pair with a given J gene.
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PMID:Structural evidence for independent joining region gene in immunoglobulin heavy chains from anti-galactan myeloma proteins and its potential role in generating diversity in complementarity-determining regions. 11 Dec 45

The digestion of human IgG1/K myeloma proteins with pepsin in the presence of 8 M-urea produces fragments that differ from those produced by aqueous peptic digestion, and from other characteristic immunoglobulin fragments. Fb'2, the larger urea/pepsin fragment, was previously shown to consist of the constant regions of the light chains, and the CH1 domains and hinge regions of the heavy chains. The smaller fragment, upFc, has now been characterized. After reduction, three peptides were released from fragment upFc. Amino acid sequencing, N- and C-terminal determinations and amino acid compositions have enabled these peptides to be identified as residues Ile-253 to Leu-306, residues Thr-307 to Asp-376 and residues Thr-411 to Gly-446 of the heavy chain. Fragment upFc therefore contains the entire Fc region, beginning at residue Ile-253, except for a 34-residue section from within the CH3-domain disulphide loop. Peptic digestion of IgG1/K proteins in 8M-urea therefore provides a method for isolating from gamma1 heavy chains five homogeneous peptides in good yield, which account for almost the entire constant region. Characterization of fragments Fb'2 and upFc has shown that the action of pepsin in urea is entirely different from that of aqueous pepsin. Two gamma1 heavy chains have been shown to differ in sequence at three positions from the sequence reported for protein Eu.
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PMID:Characterization of upFc, a fragment of human immunoglobulin G1 produced by pepsin in urea. 79 Dec 67

To study the expression of HLA-DQ beta chain alleles associated with type 1 diabetes, mAbs were generated from mice immunized with synthetic peptides representing allelic HLA-DQw7 and HLA-DQw8 beta chain sequences. The splenocytes from immunized mice were fused with myeloma cells, either immediately after or following additional in vitro boosting with peptide. Peptide-specific mAbs, predominantly of the IgG isotype, were isolated only from in vitro boosted splenocytes. Immunoblot analysis showed that several of the mAbs cross-reacted with DQ beta chain molecules. One mAb to a peptide representing DQw8 beta position [49-60] specifically recognised the DQw8 beta chain. Three mAbs to a peptide representing DQw8 beta position [39-52] specifically recognised an epitope consisting of Gly-Val-Tyr in position 45-47, i.e., all DQ beta alleles except DQw7 beta (position 45-47: Glu-Val-Tyr) and DQw2 beta (position 45-47; Gly-Glu-Phe). In FACS analysis these mAbs bound lymphocytes with the same specificity as found by immunoblotting analysis. Thus, by combining in vivo and in vitro immunization we have generated a number of epitope specific monoclonal IgG antibodies that distinguish closely related HLA-DQ beta chain alleles in predetermined positions.
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PMID:Production of epitope specific monoclonal IgG antibodies to HLA class II molecules by combining in vivo and in vitro immunization. 137 72

The latent precursor of matrilysin (EC 3.4.24.23; punctuated metalloproteinase (PUMP) was purified from transfected mouse myeloma cell conditioned medium and was found to contain one zinc atom per molecule which was essential for catalytic activity. Promatrilysin could be activated to the same specific activity by (4-aminophenyl)mercuric acetate, trypsin, and incubation at elevated temperatures (heat activation). Active matrilysin hydrolyzed the fluorescent substrate 2,4-dinitrophenyl-Pro-Leu-Gly-Leu-Trp-Ala-D-Arg-NH2 at the Gly-Leu bond with a maximum value for kcat/Km of 1.3 x 10(4) M-1 s-1 at the pH optimum of 6.5 and pKa values of 4.60 and 8.65. Activity is inhibited by the tissue inhibitor of metalloproteinases-1 in a 1:1 stoichiometric interaction. Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis in conjunction with N-terminal sequencing revealed that, as with all other matrix metalloproteinases similarly studied, promatrilysin activation was accompanied by the stepwise proteolytic removal of an M(r) 9000 propeptide from the N-terminus. The intermediates generated were dependent on the mode of activation used but, in all cases studied, activation terminated with an autocatalytic cleavage at E77-Y78 to yield the final M(r) 19,000 active matrilysin. From an analysis of the stability of the various intermediates, we propose that the sequence L13-K33 is particularly important in protecting the E77-Y78 site from autocatalytic cleavage, thereby maintaining the latency of the proenzyme.
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PMID:Biochemical characterization of matrilysin. Activation conforms to the stepwise mechanisms proposed for other matrix metalloproteinases. 139 Jun 35

A monoclonal antibody (mAb), KA8 that interacts with the kappa-opioid receptor binding site was generated. BALB/c female mice were immunized with a partially purified kappa-opioid receptor preparation from frog brain. Spleen cells were hybridized with SP2/0AG8 myeloma cells. The antibody-producing hybridomas were screened for competition with opioid ligands in a modified enzyme-linked immunosorbent assay. The cell line KA8 secretes an IgG1 (kappa-light chain) immunoglobulin. The mAb KA8 purified by affinity chromatography on protein A-Sepharose CL4B was able to precipitate the antigen from a solubilized and affinity-purified frog brain kappa-opioid receptor preparation. In competition studies, the mAb KA8 decreased specific [3H]ethylketocyclazocine ([3H]EKC) binding to the frog brain membrane fraction in a concentration-dependent manner to a maximum to 72%. The degree of the inhibition was increased to 86% when mu- and delta-opioid binding was suppressed by 100 nM [D-Ala2,NMe-Phe4,Gly-ol]-enkephalin (DAGO) and 100 nM [D-Ala2,L-Leu5]-enkephalin (DADLE), respectively, and to 100% when mu-, delta-, and kappa 2-sites were blocked by 5 microM DADLE. However, the mu-specific [3H]DAGO and the delta-preferring [3H]DADLE binding to frog brain membranes cannot be inhibited by mAb KA8. These data suggest that this mAb is recognizing the kappa- but not the mu- and delta-subtype of opioid receptors. The mAb KA8 also inhibits specific [3H]naloxone and [3H]EKC binding to chick brain cultured neurons and rat brain membranes, whereas it has only a slight effect on [3H]EKC binding to guinea pig cerebellar membranes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A monoclonal antibody recognizing kappa- but not mu- and delta-opioid receptors. 185 Dec 5

Two kappa genes, one (5.7 kb) from parental myeloma cells that were used for fusion, and the other (7.5 kb) from lymphocytes have been detected in the genome of PTF.02 hybridoma. Functionally important regions of the second gene were sequenced. In the 5'-region, positions and nucleotide sequences of the L-fragment, TAATA- and CAAT-boxes were established. Deca (dc)- and pentadecanucleotide (pd) sequences, obligatory for effective transcription of Kappa genes, were localized at the distance of 91 and 118 bp from the ATG initiating codon of the leader sequence. Together with a true pd, a shadow pd sequence was localized. This sequence was overlapped with the first sequence and shifted by one helical twist. The structure of the region of the enhancer localization was established. Comparison of this sequence with known consensus of the papova virus enhancer allows us to suggest the following structure of the enhancer core for kappa chains: TGTGGCTAA... 10 bp... TGTGGTTA. In the kappa gene under study, the variable fragment is linked to the J5 segment. In the latter, a point mutation C----G was found, to which a conservative substitution Ala - Gly in a hypervariable region of the chi-chain should correspond. Somatic mutations were also observed within the intron region adjacent to the J5 segment.
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PMID:[Regulator sequences in the kappa-chain gene expressed in the hybridoma PTF.02]. 302 80

An IgGl(lambda) Mot myeloma protein showed a unique susceptibility toward papain digestion. The Fab fragment of Mot was more digestible with papain than the Fc fragment. This phenomenon was found to occur by unusual cleavage of the Fd fragment with papain. Determination of the complete primary structure of the V region of the H chain of Mot identified two papain cleavage sites in the second complementarity-determining region (CDR). Amino acid sequence of the cleavage sites was Ser(55)-Asp-Asp-Argdecrease-Thr-Thr-Tyr-Gly-Pro-Argdecrease- Ser-Gln- (decrease = cleavage site). In the vicinity of these cleavage sites, many hydrophilic and polar residues are present and the predicted secondary structure near these cleavage sites suggested that this region was exposed on the surface of the molecule, and that the unusual papain cleavage of the IgG Mot might be caused by a unique conformation of the molecule, making it highly susceptible to enzyme digestion.
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PMID:Amino acid sequence of the variable region of heavy chain in immunoglobulin (Mot) having unusual papain cleavage sites. 308 50

We have previously reported that T helper cells of BALB/c mice recognize the unique mutated sequence Phe94, Arg95, Asn96 of the lambda 2 L chain of isologous (BALB/c) myeloma protein 315. Here we study two Id (Id-315.1.4 and Id-315.TH) of the DNP-Lys binding M315 defined by two monoclonal isologous anti-Id Ab (Ab 2-1.4 and Ab 2-TH). Both Id were (1) totally expressed by Fv-315, but not by free unpaired V domains, (2) specifically dependent on VH-315, since lambda 2-315 recombined with four other H chains did not express the Id, (3) related to the hapten-binding site because their expression was blocked by the haptens DNP-Lys and DNP-Gly, and (4) topographically related because Ab 2-1.4 and Ab 2-TH competed with each other for binding to M315. The contribution of lambda chain V regions was studied with the aid of reconstituted Ig molecules of H-315 paired with lambda 1, lambda 2, and lambda 3 L chains. Id-315.TH was expressed equally well by reconstituted Ig containing three different lambda 2 chains (lambda 2-5-7, lambda 2-T952, and lambda 2-315), but its expression was profoundly reduced when H-315 was associated with lambda 3-SAPC15 or lambda 1-J558 L chains; it therefore depended upon amino acids encoded by germline lambda 2 genes. By contrast, Id-315.1.4 was only restored by the lambda 2-315 chain paired with H-315. Since lambda 2-5-7 and lambda 2-T952 differ from lambda 2-315 at positions 38, 94, 95, 96, and 98 or 99, respectively, Id-315.1.4 probably requires the unique mutated amino acids Phe94, Arg95, Asn96 of lambda 2-315. This resembles the effects on Id expression of previously reported unique amino acids of the D region. We failed to confirm that hyperimmunization of BALB/c mice with Ab 2-1.4 cross-linked to KLH induced M315-like Ab. The results are discussed in terms of the contribution of the third hypervariable loop of lambda chains to Id and the immunogenicity of isologous Ig.
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PMID:Two M315 idiotopes defined by isologous monoclonal antibodies: one depends on germline and the other on mutated murine lambda 2 light chain sequences. 312 Mar 5

To mimic the sequence spanning the primary site (the Lys158-Ile159 bond) cleaved by plasmin in its conversion of single-chain urokinase plasminogen activator (scuPA) to urokinase, we synthesized the peptide Cys(Acm)-Leu-Arg-Pro-Arg-Phe-Lys-Ile-Ile-Gly-Gly-Glu-Phe-Cys [Cys(Acm)scuPA(153-164)Cys]. Immunization of A/J mice with the Cys(Acm)scuPA(153-164)Cys peptide linked to hemocyanin, followed by somatic cell fusion with a myeloma cell line (SP2/0), yielded a monoclonal antibody (SCOOP1) that bound to single-chain urokinase but not to urokinase or plasmin-treated single-chain urokinase. SCOOP1 could discriminate between single-chain urokinase and urokinase by greater than three orders of magnitude. In a radioimmunoassay, Cys(Acm)scuPA(153-164)Cys completely inhibited SCOOP1 binding to single-chain urokinase, whereas an equimolar mixture of two heptapeptides comprising the amino terminal [Cys-scuPA(153-158)] and carboxy terminal [scuPA(159-164)Cys)] halves of the cleavage site peptide did not. Thus the epitope recognized by SCOOP1 includes the Lys158-Ile159 peptide bond.
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PMID:A sequence-dependent monoclonal antibody specific for single-chain urokinase. 336 58

Glycopeptides have been isolated from tryptic digests of kappa-type light chains separated from human myeloma proteins obtained from the serum of two patients, Car and Rai. The glycopeptides are derived from the variable region of the chain in both cases, but from different sections. On the basis of homology it is deduced that glycopeptide from Car, kappaI type, is derived from position 25-31 whereas that from Rai, kappaII type, is from position 62-77, their sequences being respectively Ala-Ser-Gln-Asn-Ile-Ser and Phe-Ser-Gly-Ser-Gly-Ser-Gly(Thr,Asp)Phe-Thr-Leu-Asx-Ile-Ser-Arg. The significance of the results is discussed in connexion with the nature of the attachment site of carbohydrate to protein.
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PMID:Glycopeptides from human kappa-chains. 511 28


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