| 1. |
- Balbin, Milagros, et al.
(författare)
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A novel mutation in the β-protein coding region of the amyloid β-protein precursor (APP) gene
- 1992
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Ingår i: Human Genetics. - 1432-1203. ; 89:5, s. 580-582
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Tidskriftsartikel (refereegranskat)abstract
- A novel mutation, a C to T transition at base pair 2124 in exon 17 of the amyloid beta-protein precursor (APP) gene, has been identified by direct sequencing of amplified DNA from two Alzheimer's disease (AD) patients. A simple oligonucleotide-hybridization procedure was developed to allow population studies of this DNA variation. The mutation, which is silent at the protein level, was present in 2 out of 12 investigated AD patients, in 1 out of 60 non-AD patients and in 1 out of 30 healthy individuals. The mutation can be used as a new marker for linkage studies involving the APP gene, although more comprehensive population studies are required to determine the status of the mutation as a possible risk factor for the development of AD.
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| 2. |
- Balbin, Milagros, et al.
(författare)
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A sequence variation in the human cystatin D gene resulting in an amino acid (Cys/Arg) polymorphism at the protein level
- 1993
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Ingår i: Human Genetics. - 1432-1203. ; 90:6, s. 668-669
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Tidskriftsartikel (refereegranskat)abstract
- A polymorphism in the coding region of the human cystatin D gene has been detected by direct sequencing of amplified DNA from different individuals. The variation, resulting from a T/C transition in exon 1 of the gene, causes an amino acid variation, Cys/Arg, at the protein level. An allele-specific oligonucleotide hybridization assay was developed and used to demonstrate this polymorphism in the population. The deduced frequencies were 0.55 and 0.45 for the Cys and Arg variant-encoding alleles, respectively.
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| 3. |
- Balbin, Milagros, et al.
(författare)
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An Ala/Thr variation in the coding region of the human cystatin C gene (CST3) detected as a Sst II polymorphism
- 1993
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Ingår i: Human Genetics. - 1432-1203. ; 92:2, s. 206-207
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Tidskriftsartikel (refereegranskat)abstract
- A DNA variation in the coding region of the human cystatin C gene has been detected by direct sequencing. The polymorphism, a G/A transition, leads to an Ala/Thr variation in the penultimate amino acid of the signal peptide. The base substitution results in the loss of a SstII restriction site, thus allowing the design of a rapid polymerase chain reaction assay for analysis of this polymorphism in the population.
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| 4. |
- Balbin, Milagros, et al.
(författare)
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Sst II polymorphic sites in the promoter region of the human cystatin C gene
- 1991
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Ingår i: Human Genetics. - 1432-1203. ; 87:6, s. 751-752
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Tidskriftsartikel (refereegranskat)abstract
- By direct sequencing of polymerase chain reaction (PCR) amplified DNA from different individuals, three point mutations have been found in a 220-bp fragment from the promoter region of the human cystatin C gene. The three mutations are all localized within a short segment of 85 bp on the same allele. One of the base substitutions results in the generation of a novel SstII restriction site and another in the loss of the commonly occurring SstII restriction site. A PCR-based assay for analysis of the two SstII sites was designed and used to demonstrate Mendelian inheritance of the polymorphism. This SstII restriction fragment lenght polymorphism offers a new probe-independent marker for chromosome 20 linkage studies.
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| 5. |
- Balbin, Milagros, et al.
(författare)
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Structural and functional characterization of two allelic variants of human cystatin D sharing a characteristic inhibition spectrum against mammalian cysteine proteinases
- 1994
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 269:37, s. 23156-23162
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Tidskriftsartikel (refereegranskat)abstract
- Human cystatin D is a novel member of the cystatin superfamily of cysteine proteinase inhibitors present in saliva and tears. Two alleles of the cystatin D gene (CST5), encoding protein variants with either Cys or Arg as residue 26 in their 122-residue polypeptide chains, are present in the population. Expression of the two alleles was investigated by immunochemical analyses of the secreted cystatin D in saliva from individuals homozygous for each of the two alleles, with results demonstrating that both are expressed at similar levels. The inhibitory characteristics of the two cystatin D variants were studied, by determination of dissociation equilibrium constants (Ki) for their complexes with papain and with the mammalian cysteine proteinases, cathepsins B, H, L, and S. The results demonstrate that 1) cystatin D has a characteristic inhibition profile since it does not inhibit cathepsin B (Ki > 1 microM), and when compared to cystatin C and all other known cystatins it is a much poorer inhibitor of cathepsin L (mean Ki 25 nM) but binds cathepsin H and S relatively tightly (mean Ki values of 8.5 and 0.24 nM, respectively); and 2) the inhibitory activities of the two cystatin D variants are not significantly different, demonstrating that the presence of an extra cysteine residue in the cystatin D molecule affects neither the stability nor the functional activity of the inhibitor, thus explaining the widespread distribution of the Cys26-cystatin D encoding allele in the population. The inhibitory properties displayed by cystatin D suggest that it has a function in saliva as inhibitor of either endogenous or exogenous enzymes with cathepsin S- or H-like properties.
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| 6. |
- Freije, José P, et al.
(författare)
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Human cystatin D: cDNA cloning, characterization of the E. coli expressed inhibitor, and identification of the native protein in saliva
- 1993
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 268:21, s. 15737-15744
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Tidskriftsartikel (refereegranskat)abstract
- A cDNA coding for cystatin D, a human member of the cystatin protein family, has been cloned after specific amplification of reverse- transcribed parotid gland RNA. After replacing the segment encoding the putative 20-residue signal peptide with one encoding the Escherichia coli OmpA leader sequence, the cDNA was expressed in E. coli. The isolated recombinant protein exhibited Ki values of 1.2 nM and > 1 microM for papain and cathepsin B, respectively. An antiserum raised against recombinant cystatin D recognized a protein in human saliva with electrophoretical mobility identical to that of the recombinant protein. Immunoenzymatic analysis revealed that this cysteine proteinase inhibitor is present in human saliva and tears at concentrations of 3.8 and 0.5 mg/liter, respectively, while it was not detected in seminal plasma, blood plasma, milk, or cerebrospinal fluid. Cystatin D purified from human saliva by immunosorption displayed a heterogeneous N-terminal end, with sequences starting at residues 5, 7, 9, and 11 of the predicted N-terminal portion of the mature protein. On the basis of structural and functional properties, cystatin D represents a novel cysteine proteinase inhibitor possibly playing a protective role against proteinases present in the oral cavity.
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