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D Drayna

Publications and source records attributed to D Drayna.

At least 37 records · Page 2Linked to original sources
PubMed1992

A simple method for the preparation of single-stranded polydeoxynucleotides of desired length.

A method for the preparation of homogeneous, single-stranded polydeoxynucleotides of desired length up to 800 bases is described. The procedure entails 1) generation of double-stranded DNA of desired length by PCR using a pair of primers of which one is biotinylated and the other is either unlabeled or fluorescently labeled, 2) isolation of PCR products by agarose slab gel electrophoresis, 3) recovery of desired product by electroelution, 4) binding of the product to streptavidin-coated magnetic beads and is followed by 5) duplex denaturation and removal of the unbound single strand that is either unlabeled or fluorescently labeled. Final product characteristics were determined by capillary gel electrophoresis with fluorescence detection. Up to microgram quantities of homogeneous single-stranded DNA of a desired length were obtained. These can be used as single-stranded size standards in capillary gel electrophoresis experiments as well as in other techniques requiring such standards.

Base Sequence↗
PubMed1991

Isolation, molecular cloning, and partial characterization of a novel carboxypeptidase B from human plasma.

A novel plasminogen-binding protein has been isolated from human plasma utilizing plasminogen-Sepharose affinity chromatography. This protein copurified with alpha 2 antiplasmin when the plasminogen affinity column was eluted with high concentrations of epsilon-aminocaproic acid (greater than 20 mM). Analysis by sodium dodecyl sulfate suggests this protein has an apparent Mr of 60,000. The amino-terminal amino acid sequence showed no similarity to other protein sequences. Based on the amino-terminal amino acid sequence, oligonucleotide probes were designed for polymerase chain reaction primers, and an approximately 1,800 base pair cDNA was isolated that encodes this Mr 60,000 protein. The deduced amino acid sequence reveals a primary translation product of 423 amino acids that is very similar to carboxypeptidase A and B and consists of a 22-amino acid signal peptide, a 92-amino acid activation peptide, and a 309-amino acid catalytic domain. This protein shows 44 and 40% similarity to rat procarboxypeptidase B and human mast cell procarboxypeptidase A, respectively. The residues critical for catalysis and zinc and substrate binding of carboxypeptidase A and B are conserved in the Mr 60,000 plasminogen-binding protein. The presence of aspartic acid at position 257 of the catalytic domain suggests that this protein is a basic carboxypeptidase. When activated by trypsin, it hydrolyzes carboxypeptidase B substrates, hippuryl-Arg and hippuryl-Lys, but not carboxypeptidase A substrates, and it is inhibited by the specific carboxypeptidase B inhibitor (DL-5-guanidinoethyl)mercaptosuccinic acid. We propose that the Mr 60,000 plasminogen-binding protein isolated here is a novel human plasma carboxypeptidase B and that it be designated pCPB.

Amino Acid Sequence↗
PubMed1990

Restriction site polymorphism at the LPA (Lp(a) apolipoprotein; apolipoprotein (a)) locus.

A restriction site polymorphism in the Lp(a) apolipoprotein gene (the LPA gene) is reported. The basis for the polymorphism is presence or absence of an MspI restriction site that appears to be 3' to the last kringle IV structure of the gene. The "1" gene (presence of the restriction site) has a frequency of 0.316 and the "2" gene (absence of the restriction site) has a frequency of 0.684. Both members of each of 67 monozygotic (MZ) twin pairs had the same genotype and there was Mendelian segregation of the DNA variants in 40 families with a total of 75 children. There was a lower proportion of people with genotype 1-1 in the top quartile than in the 3 bottom quartiles of the population distribution of Lp(a) lipoprotein levels but the difference did not reach statistical significance.

Apolipoproteins↗
PubMed1989

DNA polymorphism at the locus for human cholesteryl ester transfer protein (CETP) is associated with high density lipoprotein cholesterol and apolipoprotein levels.

Cholesteryl ester transfer protein (CETP) is a protein involved in "reverse cholesterol transport" and it could play an important role in facilitating the removal of cholesteryl esters from peripheral tissues for transport to the liver or for transfer of cholesterol between plasma lipoprotein particles. Both functions may be relevant to susceptibility or resistance to atherosclerotic disease. We have studied 149 and 146 unrelated persons, respectively, for the A and B polymorphism at the CETP locus detectable with the restriction enzyme TaqI. The B system is by far the more polymorphic. A search for association with risk or "anti-risk" factor levels was conducted with the following quantitative parameters: total cholesterol, HDL cholesterol, triglycerides, apolipoprotein AI (apoA-I), apolipoprotein B (apoB) and Lp(a) lipoprotein levels. Highly significant differences in apoA-I concentration were found between the two categories of homozygotes in the B polymorphism. The association observed remained significant after multiplying the p value by the number of quantitative parameters used for the association tests. There was a dosage effect on the apoA-I level of genes in the B polymorphism. We conclude that the associations observed are likely to reflect true biological phenomena. The effect of CETP genes appeared to be limited to non-smokers.

Adult↗
PubMed1989

"Variability gene" effect of cholesteryl ester transfer protein (CETP) genes.

Cholesteryl ester transfer protein (CETP) may have important roles in transfer of lipids from cells to serum lipoproteins or between circulating lipoprotein particles. Restriction fragment length polymorphisms (RFLPs) in DNA at the CETP locus have been detected. In the present study we have used RFLPs detectable with the restriction enzyme TaqI to examine if CETP influences serum lipid variability (as opposed to absolute lipid levels). We have compared within-pair difference in serum lipid and apolipoprotein levels in monozygotic twin pairs of various genotypes in the B polymorphism at the CETP locus and uncovered significant differences between genotypes. We conclude that the CETP locus has "variability genes" (as opposed to "level genes") with respect to total and LDL cholesterol variability. A person's total genetic risk for coronary heart disease may depend on his or her combination of "level genes" and "variability genes". The method of analysis applied may be the best available for the study of gene - environment interaction.

Apolipoproteins↗
PubMed1987

Assignment of the human gene for cholesteryl ester transfer protein to chromosome 16q12-16q21.

We have used a cDNA probe for human cholesteryl ester transfer protein (CETP) to determine the chromosomal location for the human gene. Southern blot analysis of DNA from 17 independent mouse-human somatic cell hybrids demonstrated the presence of the gene for human CETP on chromosome 16. Regional mapping of the gene by in situ hybridization was consistent with these results and indicated that the gene resides in the 16q12-21 region of the chromosome. These findings provide an additional polymorphic marker for chromosome 16, as several relatively common restriction fragment length polymorphisms of the gene have previously been reported, and they have significance for studies directed at the identification of genetic factors affecting plasma lipoprotein metabolism and atherosclerosis.

Animals↗
PubMed1986

Cloning and expression of human apolipoprotein D cDNA.

The amino acid sequence of human apolipoprotein D, a component of high density lipoprotein, has been obtained from the cloned cDNA sequence. The 169-amino acid protein has no marked similarity to other apolipoprotein sequences, but has a high degree of homology to plasma retinol-binding protein and other members of the alpha 2u-globulin protein superfamily. Apolipoprotein D mRNA has been detected in human liver, intestine, pancreas, kidney, placenta, adrenal, spleen, and fetal brain tissue. Tissue culture cells transfected with the cloned cDNA secrete material that reacts with anti-apoD antibodies.

Amino Acid Sequence↗
PubMed1986

Human lecithin-cholesterol acyltransferase gene: complete gene sequence and sites of expression.

The human lecithin-cholesterol acyltransferase (LCAT) gene has been sequenced to completion. The gene is divided into six exons spanning approximately 4,200 bp. Exon five codes for amino acids homologous to the interfacial active site of several lipases, and also codes for an amphipathic alpha-helix resembling the carboxy terminus of apolipoprotein E. Blot hybridization data suggest that there is only one LCAT gene in humans. The 1550 base LCAT mRNA can be detected in liver and HepG2 (hepatocyte) cells, but not in small intestine, spleen, pancreas, placenta or adrenal tissue.

Base Sequence↗
PubMed1986

Cloning and expression of human lecithin-cholesterol acyltransferase cDNA.

cDNA and genomic cloning has been used to determine the mRNA and amino acid sequence of human plasma lecithin-cholesterol acyltransferase (LCATase; EC 2.3.1.43). The mature protein was found to contain 416 amino acid residues with a hydrophobic leader sequence of 24 amino acids. An unusual feature of the message is that the poly(A) signal AATAAA overlaps the COOH-terminal glutamic acid and stop codons, and the 3' untranslated region is only 23 bases. The protein itself is distinguished by a number of extended sequences of hydrophobic amino acids, one of which contains a hexapeptide identical with the interfacial binding segment of the active site of pancreatic lipase and is similar to the same site of lingual lipase. The cloned cDNA allows the expression of active LCATase by transfected tissue culture cells.

Amino Acid Sequence↗
PubMed1985

The genetic linkage map of the human X chromosome.

A database useful for mapping the human X chromosome has been established. The data consist of the genotypic characterizations obtained at more than 20 DNA marker loci from a set of 38 selected families. Multilocus linkage analysis has provided an initial genetic map completely spanning the distance from the distal short arm to the distal long arm of the chromosome, for a total genetic length of at least 185 recombination units. Analysis of the recombinational behavior of fully marked chromosomes suggests that the number of recombination events on the X chromosome may be nonrandom. Linkage studies of six families that carry the mutation which causes Duchenne muscular dystrophy were combined with linkage data from a large number of normal families. This permitted mapping of the locus for Duchenne muscular dystrophy with greater precision and statistical confidence than studies in which disease families alone provided the genotypic database. This observation suggests that the normal linkage map of this chromosome should be especially valuable in the mapping of rare X-linked diseases.

Chromosome Mapping↗
PubMed1985

A new MspI restriction fragment length polymorphism in the hemophilia B locus.

Using a partial cDNA probe for human coagulation factor IX, we have detected a new restriction fragment length polymorphism in human DNA digested with MspI. The frequency of the minor allele is 0.20 +/- 0.05 and average heterozygosity is about 0.32. The MspI RFLP is in strong linkage disequilibrium with the TaqI RFLP previously described, but should nevertheless be useful in segregation analysis in case of homozygosity for the TaqI minor allele.

Alleles↗
PubMed1985

The telomeric region of the human X chromosome long arm: presence of a highly polymorphic DNA marker and analysis of recombination frequency.

A DNA fragment (named St14) derived from the human X chromosome reveals a small family of related sequences that have been mapped to the Xq26-Xq28 region by using a panel of rodent-human somatic cell hybrids. The probe detects in human DNA digested by Taq I a polymorphic system defined by a series of at least eight allelic fragments with a calculated heterozygosity in females of 80%. With Msp I, we found three additional restriction fragment length polymorphisms, each of them being defined by two alleles. These polymorphisms are also common in Caucasian populations. The genetic locus defined by probe St14 has been localized more precisely to the distal end of the X chromosome (in band q28) by linkage analysis to other polymorphic DNA markers. The results obtained suggest that the frequency of recombination is distributed very unevenly in the q27-qter region of the X chromosome, with a cluster of seven tightly linked loci in q28 showing about 30% recombination with the gene for coagulation factor IX located in the neighboring q27 band. Probe St14 reveals one of the most polymorphic loci known to date in the human genome, and 17 different genotypes have already been observed. It constitutes the best marker on the X chromosome and should be of great use for the genetic study of three important diseases: hemophilia A, mental retardation with a fragile X chromosome, and adrenoleukodystrophy.

Alleles↗
PubMed1984

A cytological map of the human X chromosome--evidence for non-random recombination.

The cytological location of six cloned DNA sequences on the human X chromosome has been determined to a high resolution by direct hybridisation 'in situ' to metaphase chromosomes. Each locus has been identified using clones which also detect restriction fragment length polymorphisms by Southern hybridisation. The six loci identified are spaced along the chromosome from Xp22 to Xq28. By combining data obtained using this powerful sequence localisation technique with that from hybrid cell panels and from family studies, it is possible to compare physical and genetic distances, and to demonstrate that the frequency of reciprocal genetic exchange is not uniform along the chromosome length.

Base Sequence↗
PubMed1984

Genetic mapping of the human X chromosome by using restriction fragment length polymorphisms.

Using a human X chromosome-specific DNA library, we have found arbitrary single-copy DNA sequences that reveal useful restriction fragment length polymorphisms. The inheritance of these and other available polymorphic DNA markers has been studied in a series of unrelated three-generation families with large sibships. These families reveal parental phase and allow determination of recombination frequencies by counting recombinant and nonrecombinant chromosomes. The resulting genetic map indicates that the minimal distance from Xp22 to Xqter is 215 recombination units. The spacing of the marker loci is such that the majority of the loci on the X chromosome, including disease loci, will lie within 20 centimorgans of at least one of these loci.

Chromosome Mapping↗