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Biomedical subjects

B Wermuth

Publications and source records attributed to B Wermuth.

At least 55 records · Page 3Linked to original sources

Fibrinogen Milano V: a congenital dysfibrinogenaemia with a gamma 275 Arg-->Cys substitution.

An abnormal fibrinogen was discovered in a clinically asymptomatic woman from Italy. Routine coagulation studies revealed prolonged thrombin and reptilase clotting times and a discrepancy between the plasma fibrinogen levels determined by the clotting assay and electroimmunoassay. Release of fibrinopeptides A and B from fibrinogen Milano V by thrombin was normal. Fibrin polymerization was strongly delayed in the presence of EDTA and was partially corrected at physiological calcium concentration. Normal migration of mercaptolysed polypeptide chains was observed in polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. Moreover, there was no apparent abnormality in the charge of the reduced chains of the variant fibrinogen, as judged by two-dimensional gel electrophoresis. A fragment of the gamma-chain gene coding for the amino acids 259-350 was amplified and cloned. The amino acid gamma 275 arginine was found to be substituted by cysteine. Immunoblotting analysis with a rabbit antiserum against human serum albumin indicated that albumin was not linked to the odd sulphydryl group of fibrinogen Milano V. Treatment of fibrinogen Milano V with cysteamine, that is surmised to convert the mutant cysteine to a positively charged lysine analogue, did not improve the clotting properties of fibrinogen Milano V.

Afibrinogenemia↗

Autocatalytic modification of human carbonyl reductase by 2-oxocarboxylic acids.

Carbonyl reductase occurs in multiple molecular forms. Sequence analysis has yielded a carboxyethyllysine residue in one of the enzyme forms, suggesting that pyruvate has been incorporated in a posttranslational enzymatic reaction [Krook, M., Ghosh, D., Strömberg R., Carlquist, M. and Jörnvall, H. (1993) Proc. Natl. Acad. Sci. USA 90, 502-506]. Using highly purified carbonyl reductase from human brain we show that pyruvate and other 2-oxocarboxylic acids are bound to the enzyme in an autocatalytic reaction. The resulting enzyme forms were indistinguishable from the native enzyme forms by electrophoresis and isoelectric focusing.

Alcohol Oxidoreductases↗

Fibrinogen Bern I: substitution gamma 337 Asn-->Lys is responsible for defective fibrin monomer polymerization.

An inherited fibrinogen variant, fibrinogen Bern I, was isolated from plasma of an asymptomatic woman. Routine coagulation studies showed prolonged thrombin and reptilase clotting times. Fibrinogen concentration was diminished when determined by a functional assay, but was normal by the heat precipitation method. The release of fibrinopeptides A and B was not delayed. Two-dimensional gel electrophoresis of mercaptolyzed fragments D of fibrinogen, obtained by digestion with plasmin, showed an abnormal electrophoretic mobility in the gamma-chain remnants of fragments D1 and D2 from fibrinogen Bern I, whereas conversion of D2 to D3 by plasmin resulted in the loss of the abnormal charge, suggesting that the structural abnormality in this variant is located in the region gamma 303 through 356. The molecular defect in fibrinogen Bern I was identified by sequence analysis of genomic DNA amplified by polymerase chain reaction and cloned in M13mp19. The triplet AAC coding for asparagine at position gamma 337 was found to be substituted by AAA coding for lysine. We conclude that the substitution gamma 337 Asn-->Lys in fibrinogen Bern I is responsible for defective polymerization of fibrin monomers and for impaired protection by calcium against plasmic degradation.

Adult↗

Carbonyl reductase from human testis: purification and comparison with carbonyl reductase from human brain and rat testis.

Carbonyl reductase (EC 1.1.1.184) is a cytosolic, monomeric, NADPH-dependent oxidoreductase with broad specificity for carbonyl compounds and a general distribution in human tissues. A carbonyl reductase closely resembling the human enzyme is exclusively expressed in rat reproductive tissues and adrenals (Iwata, N., Inazu, N. and Satoh, T. (1989) J. Biochem. 105, 556-564). In order to investigate the relationship between the human and rat enzyme, carbonyl reductase from human testis was purified to homogeneity. The enzyme was indistinguishable from carbonyl reductase from other human tissues on the basis of physicochemical properties, substrate specificity, inhibitor sensitivity and immunological reactivity. Likewise, the human and rat testis enzymes exhibited greatly overlapping substrate specificities for prostaglandins, steroids as well as many xenobiotic carbonyl compounds, and showed the same susceptibility to inhibition by flavonoids and sulfhydryl-blocking agents. Structural homology between the two enzymes was indicated by the mutual cross-reactivity of antibodies against carbonyl reductase from one species and the enzyme protein from the other species. Unlike the rat enzyme, which is confined to Leydig cells, the human enzyme was detectable in Leydig cells as well as Sertoli and spermatogenic cells.

Alcohol Oxidoreductases↗

Isolated biotin-resistant deficiency of 3-methylcrotonyl-CoA carboxylase presenting as a clinically severe form in a newborn with fatal outcome.

The son of Kurdish, consanguineous parents (cousin marriage) presented from the first day of life with initially focal and later generalized attacks of epileptic seizures and a severe generalized muscular hypotonia. Urinary excretion of 3-hydroxyisovalerate and of 3-methylcrotonylglycine was persistently increased. Diagnosis of isolated biotin-resistant 3-methylcrotonyl-CoA carboxylase deficiency was confirmed in cultured fibroblasts. Psychomotor retardation was progressive, seizures and marked EEG abnormalities persisted. Treatment with leucine and protein-resistricted diet under hospital control did not significantly improve these conditions. The patient died from a cardiac and circulatory failure after a prolonged epileptic attack, with bronchial aspiration. The non-responsiveness of our patient to therapy and the fatal outcome indicate the existence of a severe neonatal variant of this otherwise rather benign genetic enzyme deficiency.

Amnion↗

NADP-dependent 15-hydroxyprostaglandin dehydrogenase is homologous to NAD-dependent 15-hydroxyprostaglandin dehydrogenase and other short-chain alcohol dehydrogenases.

Human tissues contain two enzymes that catalyze the oxidation of the 15-hydroxy group of prostaglandins: NAD-dependent 15-hydroxyprostaglandin dehydrogenase which is fairly specific for prostaglandins and NADP-dependent 15-hydroxyprostaglandin dehydrogenase with low specificity for prostaglandins. The recent determination of the amino acid sequence of the NAD-dependent enzyme has revealed similarities with a number of oxidoreductases with distinct specificities that constitute the short-chain alcohol dehydrogenase family. Comparison of the amino acid sequence of NADP-dependent 15-hydroxyprostaglandin dehydrogenase with the sequences of the NAD-dependent enzyme and other short-chain alcohol dehydrogenases revealed the same similarities, identifying the NADP-dependent enzyme as a short-chain alcohol dehydrogenase. The degree of homology between the two 15-hydroxyprostaglandin dehydrogenases is similar to the one between each of the two enzymes and other members of the family indicating an early evolutionary divergence of the two proteins.

Alcohol Dehydrogenase↗

Immunohistochemical localization of carbonyl reductase in human tissues.

Carbonyl reductase, an NADPH-dependent oxidoreductase of broad specificity, is present in many human tissues. Its precise localization, however, has remained unclear, as well as its physiological and possible pathophysiological significance. The present study reports the immunohistochemical localization of the enzyme in normal human tissues. Immunostaining was detectable in all organs investigated. The highest concentrations were found in the parenchymal cells of the liver, the epithelial cells of the stomach and small intestine, the epidermis, the proximal tubules of the kidney, neuronal and glial cells of the central nervous system, and certain cells of the anterior lobe of the pituitary gland. Consistently pronounced staining was also observed in smooth muscle fibers and the endothelium of blood vessels. The results are in agreement with a housekeeping function of carbonyl reductase in the elimination of reactive carbonyl compounds.

Adrenal Glands↗

Increased plasma amylase in the family of a patient with 3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency.

A patient with 3-hydroxy-3-methylglutaryl-CoA lyase (HMG-CoA lyase, EC 4.1.3.4) deficiency presented consistently above-normal values of plasma amylase (EC 3.2.1.1). Activities measured were in the lower normal range in family members not proven heterozygotes and in the upper normal range in the proven heterozygotes. Heterozygosity was proven by intermediate HMG-CoA lyase activities determined in cultured fibroblasts and in lymphocytes in the parents and the paternal grandmother. Because all of the family members had diseases of the pancreas, colon, and liver, we question whether the heterozygote state contributes to the impaired function of these organs. Our findings of significantly increased amylase activities in the heterozygotes and the patient, in comparison with the other family members, support this hypothesis.

Amylases↗

[Determination of alcohol dehydrogenase genotype: no correlation between isoenzyme pattern and liver cirrhosis].

Mounting evidence from various fields of research links the oxidation product of alcohol, acetaldehyde, with the development of alcohol abuse-related pathology. One factor governing the production of acetaldehyde is the genetically determined pattern of class I alcohol dehydrogenase isoenzymes, consisting of "fast" beta 2 and gamma 1 and "slow" beta 1 and gamma 2 subunits. Alcoholics carrying the beta 2 and gamma 1 genes might, therefore, be more susceptible to alcohol-related liver disease. To verify this hypothesis we developed a method based on the polymerase chain reaction and restriction enzyme digestion in order to genotype individuals with respect to their alcohol dehydrogenase isoenzyme pattern. In a total of 100 caucasian individuals the following genotypes were determined: beta 1 beta 1, 92; beta 1 beta 2, 8; beta 2 beta 2 0; gamma 1 gamma 1, 38; gamma 1 gamma 2, 51; gamma 2 gamma 2, 11. No statistically significant differences in the distribution of isoenzymes were detectable between alcoholics with liver disease, patients with non-alcohol abuse-related liver disease, patients with rheumatoid arthritis and healthy controls.

Alcohol Dehydrogenase↗

Human carbonyl and aldose reductases: new catalytic functions in tetrahydrobiopterin biosynthesis.

New catalytic functions of human carbonyl- and aldose reductase in tetrahydrobiopterin biosynthesis are proposed. 6-Pyruvoyl tetrahydropterin, an intermediate in the biosynthesis of tetrahydrobiopterin, was converted to 6-lactoyl tetrahydropterin and 1'-hydroxy-2'-oxopropyl tetrahydropterin by carbonyl reductase under anaerobic condition. 1'-Hydroxy-2'-oxopropyl tetrahydropterin was subsequently metabolized to tetrahydrobiopterin by aldose reductase. Based on these results alternative pathways for the synthesis of tetrahydrobiopterin in patients with genetic defects of sepiapterin reductase are suggested.

Alcohol Oxidoreductases↗

Direct and indirect mutation analyses in patients with ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) is one of 5 enzymes in the detoxification of ammonia to urea, and its deficiency, an X-linked disease, is the most common inborn error of urea genesis in humans. Because of the devastating nature of the disease there is a strong demand for reliable and rapid molecular analyses in OTC families in order to offer carrier detection and prenatal diagnosis. This paper presents the efficiency of direct and indirect mutation analyses in 22 OTC families using Southern blotting and polymerase chain reaction (PCR) amplification. For 89% of the mothers with an affected child, at least 1 RFLP of the OTC locus was informative concerning prenatal diagnosis. 100% informativity was reached by using the additional flanking markers 754 and LI.28. In total, 3 deletions (14%) and 1 TaqI site mutation (4.5%) in exon 3 were detected. 13 (60%) of our 22 mothers were found to be carriers, 9 of them being obligate carriers and 4 detected by biochemical testing. 4 mothers were excluded as carriers by DNA analyses, and in 5 mothers the carrier status could not be assessed positively. DNA analyses permitted carrier detection in 32% and carrier exclusion in 55% of 22 female relatives. Prenatal diagnosis was performed in 4 families: in 1 family by direct mutation detection and in 3 families by linkage analyses. It was possible to determine the mutation origin in 6 families, all of them with male probands. In 4 families the mutation had occurred during grandpaternal spermiogenesis, suggesting higher mutation rates in males, but in 2 cases it was the result of an event during maternal oogenesis, proving that new mutations in the OTC gene do also occur in eggs. Our recommended strategy for carrier detection and prenatal diagnosis in OTC deficiency is to examine routinely Southern blots of BamHI, EcoRI, HindIII, MspI, PstI and TaqI digestions using the OTCcDNA probe pH0731 and the flanking markers 754 and LI.28, as well as the TaqI-digested PCR products of exons 3, 5 and 9.

Base Sequence↗

Human liver 6-pyruvoyl tetrahydropterin reductase is biochemically and immunologically indistinguishable from aldose reductase.

6-Pyruvoyl tetrahydropterin reductase has been implicated in the biosynthesis of tetrahydrobiopterin. Using immunochemical and biochemical techniques the purified human liver enzyme was shown to be identical to aldose reductase. This suggests that 6-pyruvoyl tetrahydropterin reductase may play an additional role in the reduction of aldehydes derived from the biogenic amine neuro-transmitters and corticosteroid hormones as well as in the pathogenesis of diabetic complications, as has been postulated for aldose reductase.

Aldehyde Reductase↗

The aldo-keto reductase superfamily. cDNAs and deduced amino acid sequences of human aldehyde and aldose reductases.

Aldehyde reductase [EC 1.1.1.2] and aldose reductase [EC 1.1.1.21] are monomeric NADPH-dependent oxidoreductases having wide substrate specificities for carbonyl compounds. These enzymes are implicated in the development of diabetic complications by catalyzing the reduction of glucose to sorbitol. Enzyme inhibition as a direct pharmacokinetic approach to the prevention of diabetic complications resulting from the hyperglycemia of diabetes has not been effective because of nonspecificity of the inhibitors and some appreciable side effects. To understand the structural and evolutionary relationship of these enzymes, we cloned and sequenced cDNAs coding for aldose and aldehyde reductases from human liver and placental cDNA libraries. Human placental aldose reductase (open reading frame of 316 amino acids) has a 65% identity (identical plus conservative substitutions) to human liver and placental aldehyde reductase (open reading frame of 325 amino acids). The two sequences have significant identity to 2,5-diketogluconic acid reductase from corynebacterium, frog rho-crystallin, and bovine lung prostaglandin F synthase (reductase). Southern hybridization analysis of human genomic DNA indicates a multigene system for aldose reductase, suggesting the existence of additional proteins. Thus, the aldo-keto reductase superfamily of proteins may have a more significant and hitherto not fully appreciated role in general cellular metabolism.

Alcohol Oxidoreductases↗

Human carbonyl reductase. Nucleotide sequence analysis of a cDNA and amino acid sequence of the encoded protein.

Carbonyl reductase (EC 1.1.1.184) is one of several monomeric, NADPH-dependent oxidoreductases having wide specificity for carbonyl compounds that are generally referred to as the aldoketoreductases. The grouping of the enzyme into the family has been proposed on the basis of functional similarities and in the absence of structural data. Here, we describe the isolation and characterization of a cDNA clone complementary to human carbonyl reductase mRNA from a human placenta cDNA library constructed in phage lambda gt11. The cDNA consists of 1199 base pairs and contains an open reading frame encoding a protein comprised of 277 amino acids with a Mr of 30,375. The predicted amino acid sequence was confirmed by partial sequence analysis of the carbonyl reductase protein. Comparison of the protein sequence with the primary structures of other aldoketoreductases revealed no significant homologies. A possible homology, on the other hand, exists between carbonyl reductase and "short" subunit alcohol/polyol dehydrogenases.

Alcohol Oxidoreductases↗

cDNA sequence of the beta 2-subunit of human liver alcohol dehydrogenase.

A cDNA library of mRNA from a human liver expressing the beta 2-subunit of alcohol dehydrogenase was constructed in lambda gt11. One clone coding for 352 of a total of 374 amino acid residues of the beta 2-subunit was isolated. The sequence differed from that of the beta 1-subunit at one nucleotide position resulting in an Arg/His exchange at position 47 of the peptide chain, in agreement with data from protein sequence analysis [(1984) FEBS Lett. 173, 360-366].

Alcohol Dehydrogenase↗