The nomenclatures used to describe HLA and killer-cell immunoglobulin-like receptor (KIR) alleles distinguish unique nucleotide and peptide sequences, and patterns of expression, but are insufficient for describing genotyping results, as description of ambiguities and relations across loci require terminology beyond allele names. The genotype list (GL) String grammar describes genotyping results for genetic systems with defined nomenclatures, like HLA and KIR, documenting what is known and unknown about a given genotyping result. However, the accuracy of a GL String is dependent on the reference database version under which it was generated.
View Article and Find Full Text PDFNext generation sequencing (NGS) is being applied for HLA typing in research and clinical settings. NGS HLA typing has made it feasible to sequence exons, introns and untranslated regions simultaneously, with significantly reduced labor and reagent cost per sample, rapid turnaround time, and improved HLA genotype accuracy. NGS technologies bring challenges for cost-effective computation, data processing and exchange of NGS-based HLA data.
View Article and Find Full Text PDFFor over 50 years, the International HLA and Immunogenetics Workshops (IHIW) have advanced the fields of histocompatibility and immunogenetics (H&I) via community sharing of technology, experience and reagents, and the establishment of ongoing collaborative projects. Held in the fall of 2017, the 17th IHIW focused on the application of next generation sequencing (NGS) technologies for clinical and research goals in the H&I fields. NGS technologies have the potential to allow dramatic insights and advances in these fields, but the scope and sheer quantity of data associated with NGS raise challenges for their analysis, collection, exchange and storage.
View Article and Find Full Text PDFJ Am Med Inform Assoc
September 2017
Background: It is critical to integrate and analyze data from biological, translational, and clinical studies with data from health systems; however, electronic artifacts are stored in thousands of disparate systems that are often unable to readily exchange data.
Objective: To facilitate meaningful data exchange, a model that presents a common understanding of biomedical research concepts and their relationships with health care semantics is required. The Biomedical Research Integrated Domain Group (BRIDG) domain information model fulfills this need.
Genotype list (GL) Strings use a set of hierarchical character delimiters to represent allele and genotype ambiguity in HLA and KIR genotypes in a complete and accurate fashion. A RESTful web service called genotype list service was created to allow users to register a GL string and receive a unique identifier for that string in the form of a URI. By exchanging URIs and dereferencing them through the GL service, users can easily transmit HLA genotypes in a variety of useful formats.
View Article and Find Full Text PDFThe development of next-generation sequencing (NGS) technologies for HLA and KIR genotyping is rapidly advancing knowledge of genetic variation of these highly polymorphic loci. NGS genotyping is poised to replace older methods for clinical use, but standard methods for reporting and exchanging these new, high quality genotype data are needed. The Immunogenomic NGS Consortium, a broad collaboration of histocompatibility and immunogenetics clinicians, researchers, instrument manufacturers and software developers, has developed the Minimum Information for Reporting Immunogenomic NGS Genotyping (MIRING) reporting guidelines.
View Article and Find Full Text PDFWe present an electronic format for exchanging data for HLA and KIR genotyping with extensions for next-generation sequencing (NGS). This format addresses NGS data exchange by refining the Histoimmunogenetics Markup Language (HML) to conform to the proposed Minimum Information for Reporting Immunogenomic NGS Genotyping (MIRING) reporting guidelines (miring.immunogenomics.
View Article and Find Full Text PDFKnowledge of an individual's human leukocyte antigen (HLA) genotype is essential for modern medical genetics, and is crucial for hematopoietic stem cell and solid-organ transplantation. However, the high levels of polymorphism known for the HLA genes make it difficult to generate an HLA genotype that unambiguously identifies the alleles that are present at a given HLA locus in an individual. For the last 20 years, the histocompatibility and immunogenetics community has recorded this HLA genotyping ambiguity using allele codes developed by the National Marrow Donor Program (NMDP).
View Article and Find Full Text PDFThis report concerns the synthesis and chemical characterization of novel series of N-substituted 2 beta-carbomethoxy-3 beta-(4'-iodophenyl)tropane (beta-CIT, 2) analogs and their neuropharmacological evaluation for affinity at dopamine (DAT), serotonin (5-HTT), and norepinephrine membrane transporters in rat brain tissue. N-Substituted analogs of beta-CIT with a 2 beta-carbomethoxy ester moiety showed lower DAT affinity than beta-CIT for the DAT, and some were more selective for the 5-HTT over the DAT. 2 beta-Carbomethoxy(iodophenyl)nortropane analogs of beta-CIT with the N-substituents difluoroethyl, mesoxypropyl, iodopropyl, and methylpropionyl all yielded > 10-fold lower DAT affinity than beta-CIT itself, whereas the N-(fluoropropyl)-2 beta- isopropyl ester analog (1) of beta-CIT exceeded beta-CIT (2, an N-methyl-2 beta-carbomethoxy ester) in DAT affinity.
View Article and Find Full Text PDFbeta-CIT-FP [N-(3-fluoropropyl)-2 beta-carbomethoxy-3 beta-(4-iodophenyl)nortropane] is a cocaine analogue with a high affinity for the dopamine transporter. [O-methyl-11C]beta-CIT-FP ([11C]beta-CIT-FP) was prepared by O-alkylation of the free acid with [11C]methyl iodide. The total radiochemical yield of [11C]beta-CIT-FP was 50 to 60% with an overall synthesis time of 30 min.
View Article and Find Full Text PDFNative human platelet factor 4 (PF4) is a homotetrameric protein (70 residues/subunit) known for its anticoagulant heparin binding activity. 2D 15N--1H HSQC NMR experiments of native PF4 in solution show the presence of conformational heterogeneity consistent with the formation of asymmetric homo-tetramers as observed in the X-ray crystal structure of both human and bovine PF4. A chimeric mutant of PF4 (called PF4-M2) which substitutes the first 11 N-terminal residues for the first eight residues from homologous interleukin-8 forms symmetric homo-tetramers with essentially the same heparin binding activity as native PF4.
View Article and Find Full Text PDFIn an attempt to create potent and specific inhibitors of the interaction of thyrotropin (thyroid-stimulating hormone [TSH]) with its receptor, we designed a series of 18 synthetic peptides containing sequences of both alpha and beta subunits that were shown previously to interact with the TSH receptor. These "heteromeric" peptide analogs included amino acid residues from alpha 26-46, beta 31-52, beta 88-95 and beta 101-112 that were arranged variously and were separated from each other by artificial amino acid spacers. Each peptide was tested for its ability to interact with the TSH receptor in a radio-receptor assay (TSH-RRA) using porcine thyroid membranes and a bio-assay for TSH using FRTL-5 cells.
View Article and Find Full Text PDFFour N-omega-fluoroalkyl-2 beta-carboxy-3 beta-(4-iodophenyl)nortropane ester (beta-CIT-FE), N-fluoropropyl, methyl ester (beta-CIT-FP), N-fluoroethyl, isopropyl ester (IP-beta-CIT-FE), and N-fluoropropyl, isopropyl ester (IP-beta-CIT-FP)] were labeled with 125I and evaluated in baboons by dynamic SPECT regional brain imaging, measurement of pharmacokinetics in arterial plasma, and whole body imaging. The labeled tracers were prepared by iododestannylation of the corresponding 4-(trimethylstannyl)phenyl compounds in radiochemical yield 63-96% and radiochemical purity > 96%. Regional SPECT brain imaging was carried out over a period of 5 h with a Strichman 810X Brain Imager to assess regional uptake in the striatum and midbrain compared to reference regions in the occipital cortex and cerebellum; arterial blood samples were taken for analysis of metabolites by solvent extraction and HPLC.
View Article and Find Full Text PDFPlatelet factor-4 (PF4) is a 70-residue protein which contains a 3-stranded antiparallel beta-sheet domain on to which is folded a C-terminal alpha-helix and an aperiodic N-terminal region. In this study, three peptides derived from the beta-sheet (residues 24-46 and 38-57) and helix (residues 57-70) domains have been synthesized and studied in aqueous solution by CD and NMR. While peptides 24-46 and 56-70 demonstrate some weak conformational preferences, peptide 38-57 maintains a relatively well-defined, NOE-rich chain reversal sequence, L45-K46-N47-G48-R49-K50, which apparently is stabilized by hydrophobic side-chain interactions from the flanking sequences L41-L45 and I51-L53.
View Article and Find Full Text PDFComput Appl Biosci
June 1994
GOR algorithms have long been a standard methodology for predicting protein secondary structure from primary sequence. We have developed two short validation sequences for the GOR I and GOR II algorithms. Use of these sequences with seven commercial and non-commercial implementations of these algorithms demonstrated that several were incorrect implementations, including two of the three commercial modules implementing the GOR I algorithm.
View Article and Find Full Text PDFThe in vivo properties of a new radioiodinated probe of the dopamine and serotonin transporter, [123I]methyl 3 beta-(4-iodophenyl)tropane-2 beta-carboxylate ([123I]beta-CIT) were evaluated in baboons and vervet monkeys. The labeled product was prepared in 65.2 +/- 2.
View Article and Find Full Text PDFbeta-CIT (2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane) is a cocaine analogue with a high affinity for the dopamine transporter. [11C] beta-CIT was prepared by N-methylation of nor-beta-CIT with [11C]methyl iodide. The total radiochemical yield of [11C] beta-CIT was 40-50% with an overall synthesis time of 35-40 min.
View Article and Find Full Text PDFThe synthesis and pharmacological characterization of a series of N-substituted 3-(4-fluorophenyl)tropane derivatives is reported. The compounds displayed binding characteristics that paralleled those of cocaine, and several had substantially higher affinity at cocaine recognition sites. Conjugate addition of 4-fluorophenyl magnesium bromide to anhydroecgonine methyl ester gave 2 beta-(carbomethoxy)-3 beta-(4-fluorophenyl)tropane (4a, designated CFT, also known as WIN 35,428) after flash chromatography.
View Article and Find Full Text PDFMol Endocrinol
June 1990
Several regions on both the alpha- and beta-subunits of human LH comprise the receptor-binding domain of the hormone. One of these, a disulfide loop peptide containing residues 38-57 on the beta-subunit, also stimulated steroidogenesis in rat Leydig cells. Circular dichroism analysis and a Schiffer-Edmundson helical wheel projection of beta-(38-57) revealed the possibility of an amphipathic alpha-helical structure through its N-terminal region.
View Article and Find Full Text PDFPharmacol Biochem Behav
April 1990
The binding properties of three N-modified fluorophenyltropane analogs of cocaine were compared in competition experiments with [3H]cocaine. All three analogs displaced specifically bound [3H]cocaine from caudate-putamen membranes of cynomolgus monkeys with affinities exceeding that of cocaine. The compound with the highest affinity, 2 beta-carbomethoxy-3 beta-(4-fluorophenyl)-N-allyl-nortropane, (N-allyl-CFNT) was about three times more potent than cocaine.
View Article and Find Full Text PDFMost anti-nicotinic acetylcholine receptor (AChR) antibodies in myasthenia gravis are directed against an immunodominant epitope or epitopes [main immunogenic region (MIR)] on the AChR alpha-subunit. Thirty-two synthetic peptides, corresponding to the complete Torpedo alpha-subunit sequence and to a segment of human muscle alpha-subunit, were used to map the epitopes for 11 monoclonal antibodies (mAbs) directed against the Torpedo and/or the human MIR and for a panel of anti-AChR mAbs directed against epitopes on the alpha-subunit other than the MIR. A main constituent loop of the MIR was localized within residues alpha 67-76.
View Article and Find Full Text PDFIn myasthenia gravis a highly conserved area of the nicotinic receptor (AcChR) dominates the autoantibody response (main immunogenic region, MIR), and it is formed by residues within the sequence segment 67-76 of the AcChR alpha-subunit. We have studied the binding of eight anti-MIR mAb to synthetic peptides containing the sequence segment 67-76 of the human alpha-subunit, and peptide analogues containing single residue substitutions of this sequence. We used also a peptide where both Asp70 and Asp71 were substituted by glycine residues.
View Article and Find Full Text PDFThe potent cocaine analog 2 beta-carbomethoxy-3 beta-(4-fluorophenyl)-tropane (CFT, also designated WIN 35,428) was tritiated and evaluated as a molecular probe for cocaine receptors in caudate putamen membranes of cynomolgus monkeys. Kinetic, saturation, and competition experiments indicated that [3H]CFT, like [3H]cocaine, bound to at least two components. Association and dissociation of the radioligand at 0-4 degrees occurred in two phases; the t 1/2 for dissociation of the fast and slow components was 2.
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