Identical hypervariable regions in light chains of differing V kappa subgroups.
Explore the source record for details and available documents.
Amino Acid Sequence↗
SEARCH · PubMed Health
Results for “hypervariable regions”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Lack of association between the apolipoprotein B gene 3' hypervariable region alleles and coronary artery disease in Finnish patients with angiographically documented coronary artery disease.
Previous studies have suggested that some apolipoprotein B (apoB) 3' variable number of tandem repeats (3'VNTR) locus alleles are associated with coronary artery disease (CAD). We examined the possible association between the apoB 3'VNTR alleles and CAD in 387 Finnish subjects. Using the polymerase chain reaction and polyacrylamide gel electrophoresis, the 3'VNTR genotype was determined in 187 individuals with severe CAD confirmed by coronary angiography (patients), in 121 individuals with normal coronary angiograms (controls), and in 79 apparently healthy subjects (normals). In contrast to previous reports from other populations, the larger apoB 3'VNTR alleles were not significantly more frequent among CAD patients than among controls or normals. In addition, there was no significant association between the 3'VNTR alleles and serum lipid levels in this Finnish population.
Alleles↗
Peptide sequences from the hypervariable regions of two monoclonal anti-idiotypic antibodies against the thyrotropin (TSH) receptor are similar to TSH and inhibit TSH-increased cAMP production in FRTL-5 thyroid cells.
Monoclonal antibodies, D2 and 4G11, selected by the autoantiidiotypic approach following injection of thyrotropin (TSH) into mice, mimic TSH in binding to receptors on thyroid membranes. Based on TSH receptor transfection studies, D2 and 4G11 show unequivocal specificity for the TSH receptor. To see if the complementary determining regions (CDRs) of these antibodies share any primary sequence similarities to regions of TSH critical for receptor binding, we deduced the primary structure of the variable regions of D2 and 4G11 by sequencing the immunoglobulin mRNA. We found that CDR1 of 4G11K and CDR2 of D2 mu show sequence similarity to regions of TSH alpha and TSH beta that had been previously implicated in the interaction of the hormone with its receptor. We tested the inhibitory effects of synthetic peptides from D2 mu-CDR2 and 4G11K-CDR1 on the binding of the corresponding antibodies to rat thyroid FRTL-5 cells and found an EC50 of 0.1 and 1 microM, respectively. TSH-derived peptides with similarity to D2 mu-CDR2 and 4G11K-CDR1 showed a significant but lesser effect on the binding of 4G11 or D2 to thyroid cells. Additionally, we tested the effects of the CDR peptides and TSH-derived peptides on TSH-stimulated cAMP production in FRTL-5 cells and found that D2 mu-CDR2 and 4G11K-CDR1 inhibited this activity, D2 mu-CDR2 most strongly (EC50 10 microM). Thus, linear sequences from the CDRs of these autoantiidiotypic antibodies with similarity to sequences from both subunits of TSH appear to interact with the TSH receptor. These data support previous studies indicating the complexity of the interaction between TSH and its receptor and advance earlier findings that such immunologic approaches are useful in dissecting receptor-ligand interactions.
Animals↗
Amplification by the polymerase chain reaction of hypervariable regions of the human genome for evaluation of chimerism after bone marrow transplantation.
We combined the polymerase chain reaction (PCR) with oligonucleotide hybridization as a novel and sensitive technique to evaluate posttransplant chimerism. Specific oligonucleotides for hybridization were synthesized homologous to tandemly repetitive core sequences of regions with a variable number of tandem repeats (VNTRs). Polymorphisms at such loci result from allelic differences in the number of repeats. Primers flanking the repeat region of each of the corresponding VNTRs were used for amplification. Recipient and donor pretransplant DNA and recipient posttransplant DNA were amplified. The resultant fragments were analyzed after gel electrophoresis either by hybridization in-gel or after Southern transfer. To confirm our findings, we also performed standard assays of restriction fragment length polymorphisms (RFLPs). Evaluation of 13 selected cases indicated mixed chimerism (4), complete chimerism (5), recurrence of leukemia (2), and endogenous repopulation of hematopoiesis (2) after marrow transplantation. Sensitivity of the method was determined by mixing various proportions of recipient and donor DNA; the limit of detection of the minor component in a mixture was 0.1%. PCR data correlated with RFLP data in all cases except two in which PCR proved more sensitive than RFLP. PCR amplification of VNTRs combined with oligonucleotide hybridization is a novel technique for documenting posttransplant chimerism and has advantages over RFLP analysis: high sensitivity, use of small amounts of DNA (250 ng), ease of preparation of DNA, elimination of need for restriction enzymes, and the ability to complete studies in 2 days.
Base Sequence↗
[Use of DNA amplification by PCR in the study of the hypervariable region (VNTR) in a forensic medicine setting. Experience with 2 systems: Apo B and YNZ 22].
The PCR method has been applied to amplify two Variable-number-Tandem-Repeat (VNTR) sequences. The high polymorphism of these VNTR systems can be usefully applied in medical legal fields such as paternity testing and individual identification. The VNTR systems utilized were: ApoB and YNZ 22. The study was conducted on a three-generation family of thirteen members, whose relationship was previously established using conventional blood systems. The results confirm the Mendelian inheritance of the alleles found and the suitability of the PCR method for forensic purposes.
Alleles↗
Specific amino acid residues in the second hypervariable region of HLA-DQA1 and DQB1 chain genes promote the Ro (SS-A)/La (SS-B) autoantibody responses.
In order to define the HLA-DR and DQ alleles, as well as the specific DQA1 and DQB1 chain genes involved in the anti-Ro/La autoantibody responses, RFLP analysis and sequence-specific oligonucleotide typing was carried out on 58 Caucasians and 48 American blacks with SLE or Sjögren's syndrome and anti-Ro antibodies. Among both Caucasian and black patients, the highest relative risk for the anti-Ro response (both with and without accompanying anti-La) was conferred by heterozygosity for the DQw2.1 (in linkage disequilibrium with HLA-DR3) and DQw6 (a subtype of DQw1) alleles compared with either 269 normal race-matched controls or 80 anti-Ro negative SLE/Sjögren's syndrome patients. Analysis of individual DQA1 and DQB1 chain alleles revealed that DQA1*0501 and DQB1*0201 were most frequent, followed by DQA1 and DQB1 alleles comprising DQw6. In patients not possessing DQw2.1 and/or DQw6 alleles, HLA-DQB1*0302 and HLA-DQA1*0401 (especially in blacks) were significantly increased. Nucleotide sequence analysis of these associated alleles showed that 100% of patients with anti-Ro had a glutamine residue at position 34 of the outermost domain of the DQA1 chain and/or a leucine at position 26 of the outermost domain of the DQB1 chain. Patients with anti-Ro plus La were more likely to have all four of their DQA1/DQB1 chains containing these amino acid residues than either anti-Ro-negative SLE patients or controls. These data implicate specific amino acid residues on both DQA1 and DQB1 chains located in the floor of the Ag binding cleft of the HLA-DQA1:B1 heterodimer and further suggest a role for "gene dosage" in the anti-Ro (+/- La) autoantibody response.
Alleles↗
[The test for the genomic DNA of bacteriophage FD 103 detects hypervariable regions in the human genome].
Explore the source record for details and available documents.
Coliphages↗
Detection of cancer predisposition by hypervariable region analysis.
Explore the source record for details and available documents.
Alleles↗
[DNA fingerprints and hypervariable regions: genetic marker with many application potentials in medicine and biology].
DNA polymorphisms are based on variations in the nucleotide sequences of the DNA within a given population and are transmitted from parents to offspring by Mendelian inheritance. Most of these mutations are phenotypically silent. Two different types of DNA polymorphisms are restriction fragment length polymorphisms and highly variable regions (HVRs), the latter with many different alleles at a given locus. Molecular probes for HVRs (or DNA minisatellites) can detect a great number of cross-hybridising fragments dispersed throughout the genome. The polymorphic patterns of these fragments are completely individual-specific, hence termed DNA "fingerprints". DNA "fingerprinting" has been shown to be a powerful tool for establishing family relationships, for example in paternity disputes, and for the positive identification of individuals in forensic medicine. The technique may be used to document marrow engraftment in patients who have undergone allogeneic bone marrow transplantation. DNA "fingerprinting" is a new method of assessing clonality in human tumours by identifying clonal somatic mutations in the tumour DNA. Cloning of individual DNA "fingerprint" fragments yields locus-specific HVR probes which, due to their high rate of heterozygosity, are ideal for linkage analysis and prenatal diagnosis in single gene disorders. This is exemplified by adult polycystic kidney disease, which has been found by a 3'alpha-globin-HVR probe to be closely linked to the alpha-globin-gene cluster on chromosome 16p. Locus-specific HVR probes have been used for the molecular diagnosis of clonal chromosomal deletions or loss of heterozygosity at particular loci in a large variety of tumours. These findings are the basis for the identification of anti-oncogenes or putative tumour-suppressor genes in the human genome.
Animals↗
Genetic analysis of the hypervariable region flanking the human insulin gene.
In order to study the mechanisms for the generation of length diversity within the 5' flanking region of the human insulin gene, we have isolated and sequenced a previously uncharacterized allele. This allele, of a size intermediate between those three already described in the literature, encompasses 1,156 base pairs (bp) and contains 81 reiterated tandem oligonucleotides of 14-15 bp each. Population analysis on 298 independently sampled individuals by Southern blotting of genomic DNA demonstrates that the polymorphic portion of the insulin 5' flanking region varies from 400 to more than 8,000 nucleotides, being encoded by from 30 to over 540 oligomeric repeats. Length variability 5' to the insulin gene is a result primarily of unequal crossing over, which generates an expansion or contraction in the number of tandem repeat units per chromosome. A similar mechanism probably accounts for nondispersed reiterated sequences at other loci in the human genome.
Alleles↗
Sequence of a mouse germ-line gene for a variable region of an immunoglobulin light chain.
We have determined the sequence of the DNA of a germ-line gene for the variable region of a mouse immunoglobulin light chain, the VlambdaII gene. The sequence confirms that the variable region gene lies on the DNA separated from the constant region. Hypervariable region codons appear in the germ-line sequence. A sequence for the hydrophobic leader, 19 amino acids that are cleaved from the amino terminus of the protein, appears near, but not continuous with, the light chain structural sequence: most of the leader sequence is separated from the rest of the gene by 93 bases of untranslated DNA.
Animals↗
Public epitopes and the antigenic structure of the HLA molecules.
Simplified procedures for determining amino acid sequences in proteins and nucleotide sequences in DNA have rapidly expanded the number of MHC molecules for which primary amino acid structure is known. These molecules will be especially valuable as tools to study the structure-function relationships of globular proteins because of the extensive polymorphism of genes coding the MHC genes products. The general three-dimensional structure of class I MHC molecules was recently deduced, but the more subtle topographical microconformations are still undefined. Definition and topographical mapping of epitopes, defined by serological or cellular immune effector products, will be critical probes for these three-dimensional studies. Comparative studies of amino acid sequences among various MHC and molecules have revealed distinct regions of hypervariability in the alpha-1 and -2 domains of class I heavy chains and the alpha-1 and beta-1 domains of most class II molecules. Mutant MHC molecules that differ from each other by no more than one to three amino acids can have structural changes which may result in a loss of the private epitopes that defined the allelic gene product. On the basis of these studies, the private epitopes are thought to be determined by one or more of the hypervariable regions. Similar studies of the relationships between specific regions of the molecule and public epitopes are not fully explored. Because public epitopes are partially conserved structures, one might expect that their structure is not principally determined by hypervariable region. In fact, however, some public epitopes, such as A2/B17 and BW4/Bw6, do map to diversity regions. Epitope mapping as a means of identifying specific topographic sites and relating these sites to specific functional regions of the molecule will be difficult unless the epitopes themselves are better defined. Thus, the capacity to distinguish spatially distinct public epitopes from cross-reactive homologous private epitopes will be important if epitope-specific immunological probes are use to map specific regions of an MHC molecule. Many investigators are interested in the possibility that some components of HLA alloimmunization are regulated through idiotypic networks. Suciu-Foca and colleagues have provided preliminary evidence that epitope-specific HLA alloantibodies bear dominant idiotypic determinants. Antibodies to these determinants appear during pregnancy, following blood tranfusion, and following renal allograft transplantation, also, the antibodies have been correlated with renal allograft survival.(ABSTRACT TRUNCATED AT 400 WORDS)
Antibodies, Monoclonal↗
Use of a DNA probe in the diagnosis of adult polycystic kidney disease.
Adult polycystic kidney disease (APKD) is one of the most common inherited diseases in man. A diagnosis based on the demonstration of renal cysts with ultrasonography or computerised tomography may be inconclusive in early adulthood, the crucial years before child-bearing is complete. Here we describe the improved diagnostic probability that is possible using genetic linkage studies. A 24-year-old woman, whose father and younger sister were affected by APKD, was demonstrated to have a single cyst in each kidney. These findings were insufficient for a diagnosis of APKD and for this reason genetic linkage studies were undertaken. DNA was extracted from peripheral blood leukocytes from the presenting individual, and her immediate and extended family; the DNA was cut with the restriction enzyme PvuII, electrophoresed in a 0.7% agarose gel and blotted onto nitrocellulose before probing with a 32P-labelled 4 kb fragment. This contained DNA from the hypervariable region (3' hypervariable region, 3'HVR) that is linked to the gene for APKD on the short arm of chromosome 16 and has been used in other family studies by Reeders et al. We correlated the findings on Southern blotting with ultrasound evidence of APKD and found that the disease segregated with a 7.0 kb fragment in the presenting individual's father and sister. She was shown to have inherited this allele also; the use of this technique thus increased the probability of her having APKD from 50% to 96.5%.
Adult↗
Complete amino acid sequence of the variable domains of two human IgM anti-gamma globulins (Lay/Pom) with shared idiotypic specificities.
On the basis of extensive shared idiotypic specificities, two human IgM anti-gamma-globulins (Lay/Pom) were selected for complete amino acid sequence analysis of their variable domains. Previous studies on the variable regions of the heavy chains of these proteins had shown but eight amino acid differences, only one of which was within a complementarity-determining hypervariable region. The complete amino acid sequence of the variable regions of the light chains of these two proteins is the subject of this report. Protein Lay is a typical VchiI protein with only five 'framework' differences when compared with protein Roy. Protein Pom is best classified as a VchiII, but in the 'framework' there are 16 differences between it and protein Ti. Although there are extensive differences in the first hypervariable region, the second and third light-chain hypervariable regions have an identical sequence. The finding of two identical light-chain and two identical heavy-chain hypervariable regions in these two proteins, which were selected on the basis of their combining specificities and their idiotypic cross-reactions, strongly implicates hypervariable regions in the constitution of the idiotypic determinants and the antibody combining site. Additionally, the finding of identical hypervariable regions in light chains of different V-region subgroups fulfills a prediction of the gene-interaction concept of antibody variability.
Amino Acid Sequence↗
Rare sequence motifs are common constituents of hypervariable antibody regions.
An analysis of the amino acid sequences of variable regions of human and mouse antibody molecules was performed. It involved comparison of their constituent tetrapeptides with those found in a reference set (the somatic self) built with non-immunological proteins found in a protein data base. It appeared that hypervariable regions, particularly CDR1 and CDR3, are often made up of rare tetrapeptides not present in the reference set. As assessed by simple statistical tests, this bias was significant. We discuss its possible connection with the problem of antibody immunogenicity. This result provides indirect support for the existence of idiopeptides predicted by the "peptidic self model".
Amino Acid Sequence↗
Use of the asymmetric polymerase chain reaction and DNA sequencing to determine genetic variability of bean golden mosaic geminivirus in the Dominican Republic.
A combination of the polymerase chain reaction (PCR), asymmetric PCR (A-PCR) and DNA sequencing was used to determine the nucleotide sequence of a hypervariable region of the bipartite genome of bean golden mosaic geminivirus (BGMV). This region, which was part of the intergenic region of the DNA-B component, was amplified using primers designed from the nucleotide sequence of a DNA-B component clone (pDRB1) of an isolate of BGMV from the Dominican Republic (BGMV-DR). pDRB1 is infectious on beans when coinoculated with the DNA-A component of BGMV-DR (pDRA1), and typical bean golden mosaic symptoms are observed on infected plants. Bean leaf tissue infected with BGMV was collected at five separate field locations in the Dominican Republic and the hypervariable region was amplified by PCR, ssDNA was produced using A-PCR, and partial nucleotide sequences were determined. The sequences of the hypervariable region from the field-collected samples ranged from 95% (one sample) to 98% (four samples) identical to the sequence of pDRB1. This contrasts with sequence identities of 86, 75 and 46% between the pDRB1 hypervariable region and the hypervariable regions of BGMV isolates from Guatemala, Puerto Rico and Brazil respectively, and 42% with bean dwarf mosaic geminivirus. These results indicate that Dominican Republic isolates of BGMV are very similar and should be considered isolates of the same virus (BGMV-DR), and that the infectious clones of BGMV-DR are representative of BGMV isolates in the Dominican Republic. The procedures described for DNA extraction from leaf tissue and for production of high quality ssDNA using PCR and A-PCR are rapid and efficient and could be applied to studies of variability and epidemiology of other viruses.
Base Sequence↗
Diversity of light chain variable region sequences among rabbit antibodies elicited by the same antigens.
We report the complete variable region sequences of three homogeneous rabbit antibody light chains and the partial sequences of five others. Wehn these are compared to other published rabbit light chain sequences, two regions of markedly increased variability are revealed, which are homologous in position to the first and third hypervariable regions of murine and human myeloma light chains. In addition, there is increased variability among the first three residues at the aminoterminal end. A hypervariable region homologous to that identified at positions 50 to 56 in myeloma light chains is not present in these rabbit antibody light chains. The available three-dimensional models of Fab fragments based on x-ray crystallography indicate that neither the amino-terminal portion of the light chain nor the region homologous to positions 50 to 56 forms a part of the combining site. Comparison of the hypervariable regions among six light chains from antibodies to Type III pneumococcal polysaccharide and among four from antibodies to Type VIII pneumococcal polysaccharide suggests that a large number of different sequences may be found in antibodies specific for these relatively simple antigens. Certain residues outside of the hypervariable regions are invariant in the rabbit light chains and correspond to residues that are required for proper chain folding in human and murine myeloma light chains, indicating that the general conformation of myeloma light chains is the same as that of light chains of elicited antibodies.
Amino Acid Sequence↗
Characterization of the opa (class 5) gene family of Neisseria meningitidis.
Class 5 outer membrane proteins of Neisseria meningitidis show both phase- and antigenic variation of expression. The proteins are encoded by a family of opa genes that share a conserved framework interspersed with three variable regions, designated the semivariable (SV) region and hypervariable regions 1 (HV1) and 2 (HV2). In this study, we determined the number and DNA sequence of all of the opa genes of meningococcal strain FAM18, to assess the structural and antigenic variability in the family of proteins made by one strain. Pulsed field electrophoresis and Southern blotting showed that there are four opa genes in the FAM18 chromosome, and that they are not tightly clustered. DNA sequence analysis of the four cloned genes showed a modest degree of diversity in the SV region and more extensive differences in the HV1 and HV2 regions. There were four versions of HV1 and three versions of HV2 among the four genes. Each of the FAM18 opa loci contained a gene with a unique combination of SV, HV1, and HV2 sequences. We used lambda gt11 cloning and synthetic peptides to demonstrate that HV2 sequences completely encode the epitopes for two monoclonal antibodies specific for different class 5 proteins of FAM18.
Amino Acid Sequence↗