| 1. |
- Aevarsson, A, et al.
(författare)
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Ligands to the 2Fe iron-sulfur center in succinate dehydrogenase
- 1988
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Ingår i: FEBS Letters. - : Wiley. - 1873-3468 .- 0014-5793. ; 232:2, s. 298-302
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Tidskriftsartikel (refereegranskat)abstract
- Membrane-bound succinate oxidoreductases are flavoenzymes containing one each of a 2Fe, a 3Fe and a 4Fe iron-sulfur center. Amino acid sequence homologies indicate that all three centers are located in the Ip (B) subunit. From polypeptide and gene analysis of Bacillus subtillis succinate dehydrogenase-defective mutants combined with earlier EPR spectroscopic data, we show that four conserved cysteine residues in the first half of Ip are the ligands to the [2Fe-2S] center. These four residues have previously been predicted to be the ligands. Our results also suggest that the N-terminal part of B. subtilis Ip constitutes a domain which can incorporate separately the 2Fe center and interact with Fp, the flavin-containing subunit of the dehydrogenase.
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| 2. |
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| 3. |
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| 4. |
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| 5. |
- Hillarp, A, et al.
(författare)
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Protein S binding in relation to the subunit composition of human C4b-binding protein
- 1989
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793. ; 259:1, s. 6-53
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Tidskriftsartikel (refereegranskat)abstract
- The human regulatory complement component C4b-binding protein (C4BP) circulates in plasma either as a free protein or in a bimolecular complex with the vitamin K-dependent protein S. The major form of C4BP is composed of 7 identical, disulfide-linked 70 kDa subunits (alpha-chains), the arrangement of which gives the C4BP molecule a spider-like appearance. Recently, we identified a unique 45 kDa subunit (beta-chain) in C4BP. We have now isolated a subpopulation of C4BP, which does not bind protein S. This C4BP species, which had a molecular weight slightly lower than that of the predominant form, was found to lack the beta-chain. Another lower molecular weight form of C4BP was also purified. It contained the beta-chain and was efficient in binding protein S. Its subunit composition was judged to comprise six alpha-chains and one beta-chain. These results indicate C4BP in plasma to be heterogeneous at a molecular level vis-a-vis subunit composition and/or protein S binding ability and provide support for the concept that the beta-chain of C4BP contains the single protein S binding site.
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| 6. |
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| 7. |
- Lilja, H., et al.
(författare)
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Amino acid sequence of the predominant basic protein in human seminal plasma
- 1985
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793. ; 182:1, s. 181-184
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Tidskriftsartikel (refereegranskat)abstract
- The predominant basic protein in liquefied human seminal plasma is the major degradation product of the gel-forming protein secreted by the seminal vesicles. The amino acid sequence of this basic protein is presented. The basic protein contains 52 amino acid residues. It is devoid of cysteine, methionine, tryptophan, and leucine, but contains seven histidine residues located in the NH2-terminal half of the molecule. The calculated Mr of 5753 is in close agreement with that obtained from gel filtration in guanidine-HCl on Sephacryl S-200(Mr = 6000).
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| 8. |
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| 9. |
- Wieloch, Tadeusz
(författare)
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Trypsin activation of porcine procolipase. Kinetics of activation and effects on lipid binding
- 1985
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793. ; 185:1, s. 63-66
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Tidskriftsartikel (refereegranskat)abstract
- The kinetics of trypsin activation of pancreatic procolipase was investigated and the pH dependence of the binding of procolipase and colipase to a tributyrine-bile salt interface studied. The Km was 0.06 mM and Kcat 8 s-1, and was of the same order of magnitude as for the activation of pancreatic zymogens. At basic pH values colipase had a higher affinity for the tributyrine-bile salt interface as compared to procolipase. The trypsin activation of procolipase ensures a rapid degradation of dietary lipids in the intestine.
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| 10. |
- Abrahamson, Magnus, et al.
(författare)
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Molecular cloning and sequence analysis of cDNA coding for the precursor of the human cysteine proteinase inhibitor cystatin C
- 1987
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Ingår i: FEBS Letters. - : Wiley. - 1873-3468 .- 0014-5793. ; 216:2, s. 229-233
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Tidskriftsartikel (refereegranskat)abstract
- Recombinant cystatin C producing clones were isolated from a human placenta λgt11 cDNA library. The cDNA insert of one of the clones, containing 777 base pairs, encodes the complete mature cystatin C (120 amino acids) and a hydrophobic leader sequence of 26 amino acids, indicating an extracellular function of the inhibitor. The deduced protein sequence confirms the protein sequence of cystatin C isolated from human urine, but differs in one position from the sequence of the cystatin C fragment deposited as amyloid in hereditary cerebral hemorrhage with amyloidosis.
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| 11. |
- Hederstedt, Lars, et al.
(författare)
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Processing of Bacillus subtilis succinate dehydrogenase and cytochrome b-558 polypeptides
- 1987
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Ingår i: FEBS Letters. - : Wiley. - 1873-3468 .- 0014-5793. ; 213, s. 385-390
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Tidskriftsartikel (refereegranskat)abstract
- The DNA sequence of the Bacillus subtilis sdh operon coding for the two succinate dehydrogenase subunits and cytochrome b-558 (the membrane anchor protein) has recently been established. We have now determined the extent of N-terminal processing of each polypeptide by radiosequence analysis. At the same time, direct evidence for the correctness of the predicted reading frames has been obtained. The cytochrome showed a ragged N-terminus, with forms lacking one residue, and is inserted across the membrane without an N-terminal leader-peptide. Covalently bound flavin was not detectable in B. subtilis succinate dehydrogenase expressed in Escherichia coli despite normal N-terminal processing of the apoprotein. This provides an explanation to why the succinate dehydrogenase synthesized in E. coli is not functional and demonstrates that host-specific factors regulate the coenzyme attachment.
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| 12. |
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Principato, Giovanni B, et al.
(författare)
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Relaxed thiol substrate specificity of glutathione transferase effected by a non-substrate glutathione derivative
- 1988
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 231:1, s. 155-158
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Tidskriftsartikel (refereegranskat)abstract
- Rat glutathione transferase 4-4 catalysed the conjugation of 2-mercaptoethanol with 1-chloro-2,4-dinitrobenzene in the presence of S-methyl-glutathione. The reaction was linearly dependent on enzyme concentration and saturation was seen with respect to both 2-mercaptoethanol and S-methyl-glutathione concentration. High concentrations of S-methyl-gluta-thione were inhibitory. The results suggest that the natural substrate glutathione has two distinct functions in the normal catalytic reaction, (i) induction of a catalytically competent conformation of the enzyme and (ii) provision of the substrate sulfhydryl group in the reaction catalyzed.
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| 19. |
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| 20. |
- Syvänen, Ann-Christine, et al.
(författare)
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Direct sequencing of affinity-captured amplified human DNA application to the detection of apolipoprotein E polymorphism
- 1989
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 258:1, s. 71-74
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Tidskriftsartikel (refereegranskat)abstract
- We describe a method for the direct sequencing of DNA amplified by the polymerase chain reaction (PCR). Biotin is introduced into one strand of the amplified DNA using a 5'-biotinylated PCR primer. The synthesized fragment is captured on an avidin-matrix and rendered single stranded, whereafter the nucleotide sequence of the immobilized strand is determined by the chain termination method. The method involves few and simple operations and is thus applicable to the analysis of human genes for routine diagnostic purposes. Here we applied the method for determination of the three-allelic polymorphism of the apolipoprotein E (apo E) gene. We were able to correctly identify the alleles in both homozygous and heterozygous samples.
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| 21. |
- Askerlund, Per, et al.
(författare)
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Localization of donor and acceptor sites of NADH dehydrogenase activities using inside-out and right-side-out plasma membrane vesicles from plants
- 1988
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 239:1, s. 23-28
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Tidskriftsartikel (refereegranskat)abstract
- Inside-out and right-side-out plasma membrane vesicles from sugar beet (Beta vulgaris L.) leaves, prepared by aqueous two-phase partitioning, were used to localize donor and acceptor sites and to determine substrate affinities for plasma membrane-bound NADH dehydrogenase activities. NADH-ferricyanide and NADH-cytochrome c reductase activities were approx. 30% latent with inside-out vesicles and about 80% latent with right-side-out vesicles, indicating that both donor and acceptor sites for these activities are located on the cytoplasmic surface of the plasma membrane, and that a possible transplasma membrane electron transport would constitute only a minor proportion of the total activity.
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| 22. |
- Bläckberg, Lars, et al.
(författare)
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Further characterization of the bile salt-stimulated lipase in human milk
- 1983
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 157:2, s. 337-341
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Tidskriftsartikel (refereegranskat)abstract
- Bile salt-stimulated lipase is a milk enzyme unique to the higher primates. Its molecular and kinetic characteristics differ greatly from other lipolytic enzymes; e.g., pancreatic lipase and lipoprotein lipase. It has a much higher app. Mr, 310000 on gel filtration and 100000 after denaturation. It requires primary bile salts for optimal activity and bile salts also protect the enzyme from proteolytic and heat inactivation. It may, due to its low substrate specificity, contribute to the utilization of a variety of milk lipids. Since it lacks positional specificity, digestion of milk triglycerides should be complete, which may explain why fat absorption is more efficient in breast-fed than in formula-fed infants.
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| 23. |
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| 24. |
- Jönsson, L., et al.
(författare)
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Trametes versicolor ligninase: isozyme sequence homology and substrate specificity
- 1989
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Ingår i: FEBS Letters. - 0014-5793 .- 1873-3468. ; 247:1, s. 143-146
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Tidskriftsartikel (refereegranskat)abstract
- The substrate specificity of three ligninase isozymes from the white-rot fungus Trametes versicolor has been investigated using stereochemically defined synthetic dimeric models for lignin. The isozymes have been found to attack non-phenolic β-O-4 as well as β-1 lignin model compounds. This finding confirms the classification of the isozymes from T. versicolor as ligninases. The amino-terminal residues of the three isozymes from T. versicolor have been determined using Edman degradation. Minor differences found between the sequences suggest the existence of several structural genes for ligninase in T. versicolor. Comparisons have been made with the sequences of three previously reported ligninases from Phanerochaete chrysosporium, another lignin-degrading fungus. One of the sequences from P. chrysosporium is distinctly more similar to the T. versicolor isozymes than to the other two sequences from P. chrysosporium.
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| 25. |
- Nilsson Ekdahl, Kristina, et al.
(författare)
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The effect of fructose-2,6-bisphosphate and AMP on unphosphorylated and phosphorylated fructose-1,6-bisphosphatase from rat liver
- 1984
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Ingår i: FEBS Letters. - : Wiley. - 0014-5793 .- 1873-3468. ; 167:2, s. 203-209
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Tidskriftsartikel (refereegranskat)abstract
- Rat liver fructose-1,6-bisphosphatase was partially phosphorylated in vitro and separated into unphosphorylated and fully phosphorylated enzyme. The effects of fructose 2,6-bisphosphate and AMP on these two enzyme forms were examined. Unphosphorylated fructose-1,6-bisphosphatase was more easily inhibited by both effectors. Fructose 2,6-bisphosphate affected both K0.5 and Vmax, while the main effect of AMP was to lower Vmax. Fructose 2,6-bisphosphate and AMP together acted synergistically to decrease the activity of fructose-1,6-bisphosphatase, and since unphosphorylated and phosphorylated enzyme forms are affected differently, this might be a way to amplify the effect of phosphorylation.
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| 26. |
- Nånberg, Eewa, 1957-, et al.
(författare)
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Alpha 1-adrenergic activation of brown adipocytes leads to an increased formation of inositol polyphosphates
- 1986
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Ingår i: FEBS Letters. - : Elsevier. - 0014-5793 .- 1873-3468. ; 195:1-2, s. 319-322
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Tidskriftsartikel (refereegranskat)abstract
- alpha 1-Adrenergic activation of isolated brown adipocytes causes a rapid mobilization of intracellular Ca2+. The cells also respond with an increased turnover of inositol lipids. The present work demonstrates that alpha 1-adrenergic stimulation of brown adipocytes results in phospholipase C-mediated breakdown of phosphatidylinositol bisphosphate to form inositol trisphosphate. The rate of appearance of inositol trisphosphate is sufficiently rapid for it to mediate or contribute to Ca2+ mobilization in these cells.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Bläckberg, L, et al.
(författare)
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Bile-salt-stimulated lipase in human milk : evidence for its synthesis in the lactating mammary gland.
- 1987
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Ingår i: FEBS Letters. - 0014-5793 .- 1873-3468. ; 217:1, s. 37-41
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Tidskriftsartikel (refereegranskat)abstract
- Human milk contains many enzymes and other biologically active proteins. One of the enzymes, the bile salt-stimulated lipase, constitutes as much as 1% of the milk proteins. Its importance for efficient utilization of milk lipids by the breast-fed infant is now well established. However, whether the lipase protein is a product of protein synthesis within the mammary gland has up till now been an unanswered question. Using biopsy material from lactating human mammary gland we have now demonstrated that the enzyme is synthesized within the gland. This was done by immunoprecipitation of [35S]methionine-labelled protein from tissue pieces. By activity determination we could also determine the amount of enzyme stored in the gland. It was concluded that bile salt-stimulated lipase accounted for 1.3 micrograms/mg tissue protein. Finally, from this figure it could be calculated that about 10-15% of the total protein present in the tissue was milk protein.
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| 31. |
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| 32. |
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| 33. |
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| 34. |
- Breimer, Michael, 1951, et al.
(författare)
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Structural characterization of a blood group A heptaglycosylceramide with globo-series structure. The major glycolipid based blood group A antigen of human kidney.
- 1985
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Ingår i: FEBS letters. - 0014-5793. ; 179:1, s. 165-72
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Tidskriftsartikel (refereegranskat)abstract
- A blood group A glycosphingolipid with the globo-series structure has been isolated from human kidney and structurally characterized. The structure was shown by mass spectrometry and proton NMR spectroscopy of the intact permethylated and permethylated-reduced derivatives together with degradation studies to be, GalNAc alpha 1----3Gal(2----1 alpha Fuc)beta 1----3GalNAc beta 1----3Gal alpha 1----4Gal beta 1----4Glc beta 1----1 Ceramide. This glycolipid reacts with both polyclonal and monoclonal anti-A blood group typing antisera and it is the major glycolipid based blood group A antigen present in the human kidney.
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| 35. |
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| 36. |
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| 37. |
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| 38. |
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