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Current Medicinal Chemistry 2012Transthyretin (TTR), a β-strand rich tetrameric protein present in human serum and cerebrospinal fluid is involved in the transport of thyroxine and retinol binding... (Review)
Review
Transthyretin (TTR), a β-strand rich tetrameric protein present in human serum and cerebrospinal fluid is involved in the transport of thyroxine and retinol binding protein:retinol complex (holo-RBP). TTR forms two T4 binding sites at the center of the dimer-dimer interface and contains holo-RBP binding sites on both faces of the tetramer. Dissociation of TTR tetramers followed by misfolding and misassembly results in amyloid fibril formation, the causative agent of four neurodegenerative diseases. Misfolding of wild type TTR in humans over 60 years of age is linked to a sporadic amyloid disease called senile systemic amyloidosis. Single point mutations enhance the amyloidogenicity of TTR, causing familial amyloid cardiomyopathy, familial amyloid polyneuropathy, and central nervous system selective amyloidosis. To date, nearly 200 X-ray crystal structures of TTR and their complexes have been solved. They have provided potential insights into its structure-function relationships with molecular partners, and its interactions with small molecule ligands that inhibit tetramer destabilization and amyloid formation. This review will focus on the key findings of the structural studies of TTR that provided atomic level description of its architecture, the mechanistic role of structural components involved in its function and misfolding, and the progress and limitations towards the design of selective inhibitors for TTR amyloidoses.
Topics: Amyloidosis; Binding Sites; Drug Design; Humans; Models, Molecular; Molecular Structure; Prealbumin; Protein Binding; Protein Folding
PubMed: 22471981
DOI: 10.2174/092986712800269335 -
Clinical Chemistry and Laboratory... Dec 2002Choroid plexus has the highest concentration of transthyretin (TTR) mRNA in the body, 4.4 microg TTR mRNA/g wet weight tissue, compared with 0.39 microg in the liver.... (Review)
Review
Choroid plexus has the highest concentration of transthyretin (TTR) mRNA in the body, 4.4 microg TTR mRNA/g wet weight tissue, compared with 0.39 microg in the liver. The proportion of TTR to total protein synthesis in choroid plexus is 12%. All newly synthesized TTR is secreted towards the ventricles. Net transfer of T4 occurs only towards the ventricle and depends on ongoing protein synthesis. Thyroxine-binding globulin (TBG), TTR and albumin form a "buffering" system for plasma [T4] because of their overlapping affinities and on/off rates for L-thyroxine (T4)-binding. The individual components of this network determining T4 distribution are functionally highly redundant. Absence of TBG (humans), or TTR (mice), or albumin (humans, rats) is not associated with hypothyroidism. Natural selection is based on small, inheritable alterations improving function. The study of these alterations can identify function. TTR genes were cloned and sequenced for a large number of vertebrate species. Systematic, stepwise changes during evolution occurred only in the N-terminal region, which became shorter and more hydrophilic. Simultaneously, a change in function occurred: TTR affinities for T4 are higher in mammals than in reptiles and birds. L-triiodothyronine (T3) affinities show the opposite trend. This favors site-specific regulation of thyroid hormones by tissue-specific deiodinases in the brain.
Topics: Animals; Base Sequence; Choroid Plexus; Evolution, Molecular; Humans; Molecular Sequence Data; Prealbumin; Species Specificity; Thyroid Hormones
PubMed: 12553420
DOI: 10.1515/CCLM.2002.210 -
Biochemical and Biophysical Research... Sep 1991Naturally occurring variants of human serum transthyretin (prealbumin) have been prepared by recombinant DNA methods and crystallized from ammonium sulfate solutions to...
Naturally occurring variants of human serum transthyretin (prealbumin) have been prepared by recombinant DNA methods and crystallized from ammonium sulfate solutions to give crystals suitable for x-ray crystallographic analysis. Included are variants which are known to be associated with familial amyloidotic polyneuropathy. Dyes which have been used as histochemical stains to identify amyloid tissue deposits: Congo Red, Methylene Blue and Bromophenol Blue, have been co-crystallized with the transthyretin variants. Congo Red was found to be very selective while Methylene Blue actually assisted in the formation of crystals. All crystal forms which were examined were isomorphous to the structure of normal transthyretin.
Topics: Base Sequence; Crystallization; Crystallography; Escherichia coli; Humans; Molecular Sequence Data; Mutagenesis, Site-Directed; Plasmids; Prealbumin; Recombinant Proteins
PubMed: 1898403
DOI: 10.1016/0006-291x(91)91888-j -
Biochemical and Biophysical Research... Apr 2022Familial amyloidotic polyneuropathy (FAP) is caused by a mutation in the transthyretin (TTR) gene. In addition, deposition of wild-type TTR can cause senile systemic...
Familial amyloidotic polyneuropathy (FAP) is caused by a mutation in the transthyretin (TTR) gene. In addition, deposition of wild-type TTR can cause senile systemic amyloidosis (SSA). To date, we have produced several transgenic mouse models for FAP and SSA by introducing TTR genes with different promoters or mutations. However, mouse TTR can associate with human TTR to produce hybrid tetramers in transgenic mice. Thus, these transgenic mice cannot be used to test the efficacy of a new therapy. In this study, we attempted to construct an optimized mouse model to verify a new therapy. The TTR gene consists of 4 exons and 3 introns. We prepared two gRNAs, one for the exon 1 and the other for exon 4, and a single donor vector carrying the whole TTR gene in which mouse exons were replaced with human exons. Using these vectors, we produced a TTR exon-humanized mouse with human exons and mouse introns using genome editing technology. These TTR exon-humanized mice showed normal TTR expression patterns in terms of serum TTR level and spatial specificity. These TTR exon-humanized mice will be useful for devising new treatment methods for FAP, including gene therapy.
Topics: Animals; Disease Models, Animal; Exons; Gene Expression Regulation; Humans; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Transgenic; Polyneuropathies; Prealbumin; RNA, Guide, CRISPR-Cas Systems; Mice
PubMed: 35176627
DOI: 10.1016/j.bbrc.2022.02.035 -
Clinical Chemistry and Laboratory... Dec 2002Serum transthyretin is an ideal marker for monitoring patients who are malnourished or have metabolic consequences of acute stress injury because it has a short... (Review)
Review
Serum transthyretin is an ideal marker for monitoring patients who are malnourished or have metabolic consequences of acute stress injury because it has a short half-life, it measures the level of metabolic deficit, the response to nutritional metabolic support, and because it is a prognostic indicator. Mounting clinical evidence indicates that the use of transthyretin to assess and monitor a patient's nutritional status results in improved treatment outcomes and lower overall healthcare costs.
Topics: Health Care Costs; Humans; Monitoring, Physiologic; Prealbumin; Protein-Energy Malnutrition; Stress, Physiological
PubMed: 12553442
DOI: 10.1515/CCLM.2002.232 -
Accounts of Chemical Research Dec 2005Small molecule-mediated protein stabilization inside or outside of the cell is a promising strategy to treat protein misfolding/misassembly diseases. Herein we focus on... (Review)
Review
Small molecule-mediated protein stabilization inside or outside of the cell is a promising strategy to treat protein misfolding/misassembly diseases. Herein we focus on the transthyretin (TTR) amyloidoses and demonstrate that preferential ligand binding to and stabilization of the native state over the dissociative transition state raises the kinetic barrier of dissociation (rate-limiting for amyloidogenesis), slowing and in many cases preventing TTR amyloid fibril formation. Since T119M-TTR subunit incorporation into tetramers otherwise composed of disease-associated subunits also imparts kinetic stability on the tetramer and ameliorates amyloidosis in humans, it is likely that small molecule-mediated native state kinetic stabilization will also alleviate TTR amyloidoses.
Topics: Amyloidosis; Binding Sites; Drug Design; Humans; Kinetics; Prealbumin; Protein Conformation; Protein Folding; Structure-Activity Relationship; Thyroxine
PubMed: 16359163
DOI: 10.1021/ar020073i -
Current Eye Research Jul 1991A chromatographic method for separating tear specific prealbumin (TSP) into six isoelectric forms is described. Size exclusion high performance liquid chromatography...
A chromatographic method for separating tear specific prealbumin (TSP) into six isoelectric forms is described. Size exclusion high performance liquid chromatography (SE-HPLC) was used to isolate TSP from whole tears, followed by chromatofocusing fast protein liquid chromatography (FPLC) of the SE-TSP fraction on a Mono P column. This yielded six fractions varying in isoelectric point (pI) between 5.3 and 4.6. Subsequent anion exchange FPLC (Mono Q column) allowed a slight further purification of each Mono P fraction and removed Polybuffer from the Mono P fractions. Isoelectric focusing (IEF) of the TSP isoforms verified that the heterogeneity was based on pI, and confirmed that the chromatofocusing separation was in many respects the same as an IEF separation. Purity of TSP isoforms was determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), IEF, enzyme-linked immunosorbent assay (ELISA) and immunoblotting of samples separated by SDS-PAGE and IEF. Amino acid analysis and N-terminal amino acid sequencing revealed subtle differences between the TSP isoforms. The entire purification procedure was conducted both with and without the addition of reducing agents and protease inhibitors to tear samples and all buffers used in the purification process. Relatively little difference was seen in the TSP isoform profile under these two sets of conditions. However, the tendency of isolated TSP to aggregate and precipitate was dramatically decreased under reducing conditions, resulting in significantly higher protein recoveries. This chromatographic purification procedure provides a basis for further study of the nature of the heterogeneity of TSP and characterization of the properties of this protein.
Topics: Amino Acid Sequence; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Humans; Immunoblotting; Isoelectric Focusing; Isoelectric Point; Molecular Sequence Data; Neuraminidase; Prealbumin; Tears
PubMed: 1914498
DOI: 10.3109/02713689109013853 -
Science (New York, N.Y.) Jul 2021
Topics: Aged; Amyloid Neuropathies, Familial; CRISPR-Cas Systems; Clinical Trials as Topic; Female; Gene Editing; Humans; Injections; Liver; Male; Middle Aged; Mutation; Prealbumin; Protein Folding; RNA, Messenger
PubMed: 34210861
DOI: 10.1126/science.373.6550.16 -
Methods in Molecular Biology (Clifton,... 2023Characterization of oligomeric intermediate states populated at an early stage of misfolding and aggregation is essential to understanding molecular mechanism of...
Characterization of oligomeric intermediate states populated at an early stage of misfolding and aggregation is essential to understanding molecular mechanism of pathogenic protein aggregation. Growing evidence also suggests that oligomeric species are more toxic than mature fibrillar counterparts. Here, we describe procedures for isolating oligomeric species of an aggregation-prone protein, transthyretin, associated with protein misfolding disorders, including cardiomyopathy and polyneuropathy. We also describe methods for structural studies of the oligomeric species using circular dichroism and solid-state NMR spectroscopy. These methods can be applied to structural characterization of oligomeric intermediates of other aggregation-prone proteins.
Topics: Prealbumin; Amyloid; Magnetic Resonance Spectroscopy; Circular Dichroism; Protein Aggregates
PubMed: 36310212
DOI: 10.1007/978-1-0716-2597-2_21 -
Archives of Biochemistry and Biophysics Oct 1989According to recent studies on protein chemistry and genetic engineering, replacement of the Val30 residue of prealbumin by methionine is believed to play a critical...
According to recent studies on protein chemistry and genetic engineering, replacement of the Val30 residue of prealbumin by methionine is believed to play a critical role in the formation of amyloid deposit and the pathogenesis of familial amyloidotic polyneuropathy (FAP). However, only limited information is available concerning the behavior of prealbumin in the circulation. To obtain the molecular insight into the mechanism of amyloid deposition, it is indispensable to know the fates of normal and variant prealbumin in vivo. Thus, the fates of prealbumin samples from normal and FAP patients were studied in normal rats as well as in animals that were challenged with acute inflammation induced by turpentine. The effect of in vitro photooxidation of prealbumin samples on their behavior was also examined in vivo. Kinetic analysis revealed no appreciable difference between prealbumin samples from normal and FAP patients. These results suggest that factors other than the rate of transfer of the variant form prealbumin from plasma to an extravascular compartment may play a critical role in the pathogenesis of amyloid deposition in FAP patients.
Topics: Amyloidosis; Animals; Genetic Variation; Humans; Inflammation; Male; Nervous System Diseases; Oxidation-Reduction; Photochemistry; Prealbumin; Rats; Rats, Inbred Strains; Reference Values; Tissue Distribution; Valine
PubMed: 2774586
DOI: 10.1016/0003-9861(89)90418-9