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5. Kohlensäureübertragung durch Biotinenzyme

Author

Knappe, J., Lynen, F., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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6. Schlußwort

Author

Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., Sund, Horst, Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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9. Mechanismen Enzymatischer Reaktionen

Author

Wieland, Th., primary, Wallenfels, Kurt, additional, Streffer, Christian, additional, Bender, Myron L., additional, Fasold, H., additional, Gröschel-Stewart, U., additional, Gundlach, G., additional, Turba, F., additional, Rabin, B. R., additional, Mathias, A. P., additional, Witzel, Herbert, additional, Veeger, C., additional, Hemmerich, Peter, additional, Jaenicke, L., additional, Kohlhaw, G., additional, Holzer, H., additional, Schröter, W., additional, Knappe, J., additional, Lynen, F., additional, Clark, V. M., additional, Prelog, V., additional, Pfleiderer, G., additional, and Sund, Horst, additional

Published
1964
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11. Stable glycyl radical from pyruvate formate-lyase and ribonucleotide reductase (III)

Author

Knappe J and Wagner Af

Subjects
chemistry.chemical_classification, biology, Stereochemistry, Radical, Reductase, Cofactor, chemistry.chemical_compound, Residue (chemistry), Enzyme, Ribonucleotide reductase, chemistry, Biochemistry, Glycine, biology.protein, DNA
Abstract

Publisher Summary This chapter reviews the protein chemical and functional similarities between the glycyl radicals of pyruvate formate-lyase (PFL) and ribonucleotide reductase (RNR) III. In catalyzing quite different chemical reactions, the two enzymes illustrate the broad utilization potential that nature has apparently exploited for this cofactor. The investigations of the two enzyme systems have revealed the principles of how the glycyl radical cofactor is generated, stabilized, and utilized to promote the transformation of organic molecules along the radical-chemical reaction coordinates. The selection of the simple glycine residue as a radical storage element for the chemical purpose of transferring hydrogen atoms must be an ancient stratagem in the evolution of life. While glycyl radical enzymes are distributed today among many classes of organisms, but restricted to anaerobes a “ur-ribonucleotide reductase” probably of the class III type is presently proposed as a prerequisite for the first appearance of DNA. The sequences of extant PFL and anaerobic RNR enzymes suggest divergent evolution of these proteins.

Published
2001

12. Structure and mechanism of the glycyl radical enzyme pyruvate formate-lyase

Author

Becker, A., Fritz-Wolf, K., Kabsch, W., Knappe, J., Schultz, S., and Wagner, A.

Abstract

Pyruvate formate-lyase (PFL) from Escherichia coli uses a radical mechanism to reversibly cleave the C1-C2 bond of pyruvate using the Gly 734 radical and two cysteine residues (Cys 418, Cys 419). We have determined by X-ray crystallography the structures of PFL (non-radical form), its complex with the substrate analog oxamate, and the C418A,C419A double mutant. The atomic model (a dimer of 759-residue monomers) comprises a 10-stranded beta/alpha barrel assembled in an antiparallel manner from two parallel five-stranded beta-sheets; this architecture resembles that of ribonucleotide reductases. Gly 734 and Cys 419, positioned at the tips of opposing hairpin loops, meet in the apolar barrel center (Calpha-Sgamma = 3.7 A). Oxamate fits into a compact pocket where C2 is juxtaposed with Cys 418Sgamma (3.3 A), which in turn is close to Cys 419Sgamma (3.7 A). Our model of the active site is suggestive of a snapshot of the catalytic cycle, when the pyruvate-carbonyl awaits attack by the Cys 418 thiyl radical. We propose a homolytic radical mechanism for PFL that involves Cys 418 and Cys 419 both as thiyl radicals, with distinct chemical functions.

Published
1999

21. Structure and Function of Carbamoylphosphate Synthetase: On the Mechanism of Bicarbonate Activation.

Author

Guthöhrlein, G. and Knappe, J.

Subjects
*CHEMICAL structure, *LIGASES, *BICARBONATE ions, *AMMONIUM, *ADENOSINE triphosphatase, *HYDROLYSIS, *CATALYSIS
Abstract

The Km-values for ammonium and bicarbonate in carbamoylphosphate synthesis are 1.1 mM and 5.3 mM respectively at saturation with ATP and acetylglutamate. The are independent of the concentration of the second substrate. The same Km for bicarbonate is found in the hydrolysis of ATP, which is catalyzed by the enzyme in the absence of ammonium. The [32P]orthophosphate- ATP-exchange, which is very slow, requires bicarbonate and ammonium. With these findings, the following mechanisms for the C—N-ligase step(s) of the enzyme are possible: (a) enzyme-bound carbamate is formed by a simultaneous reaction of ATP, bicarbonate and ammonium; (b) at first enzyme-bound "active CO2" is formed in a rapid and reversible reaction, which releases both the ATP-products, ADP and orthophosphate only upon the reaction with ammonium. Possible structures for this intermediate would be carboxyphosphate plus ADP and the addition compound of bicarbonate with ATP (with penta-coordinated phosphorus). The participation of biotin was excluded. As can be estimated from the kinetic findings, only a small fraction of the enzyme molecules would ever be charged with "active CO2": the half-time of its decomposition, as calculated from the ATPase activity, would be ≤ 2 sec. [ABSTRACT FROM AUTHOR]

Published
1969
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22. Structure and Function of Carbamoylphosphate Synthase 1. Transitions between two Catalytically Inactive Forms and the Active Form.

Author

Guthöhrlein, G. and Knappe, J.

Subjects
*CATALYSIS, *ENZYMES, *MOLECULAR weights, *ADENOSINE triphosphatase, *TEMPERATURE, *LOW temperatures
Abstract

Carbamoylphosphate synthase of rat liver has been purified to a homogeneous state its molecular weight as about 250,000. When the catalytic activity is measured at 10°, using an optical method, an activation phase is detectable which could be assigned to the N-acetyl-glutamate induced transition of the enzyme from an inactive conformation to the active conformation. The half-time of the process is about 1 mm at 10 mM acetyl-glutamate. The specific effect of the cofactor was found to be the labilization of the inactive conformation (as opposed to a stabilization of the active conformation). At low temperatures the enzyme dissociates reversibly into probably two a identical subunits. The dissociation seems to occur at the stage of the active conformation, ATP was found to hold back the dissociation by specifically stabilizing the active conformation. [ABSTRACT FROM AUTHOR]

Published
1968
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25. Die biochemische Funktion des Biotins

Author

E. Lorch, Knappe J, Ringelmann E, Feodor Lynen, and G. Jütting

Subjects
General Medicine
Abstract

Zu den wenigen Vitaminen, deren biochemische Funktion bisher ungeklart war, gehort das Biotin. Es wurde nun gefunden, das das Enzym β-Methyl-crotonyl-CoA-Carboxylase Biotin enthalt und das dieses mit der Wirkgruppe des Enzyms identisch ist. Durch Austauschversuche mit radioaktiv markierten Verbindungen konnte nachgewiesen werden, das bei der Carboxylierung intermediar aktives CO2 in Form einer CO2 ∼ Biotin-Enzym-Verbindung entsteht. Am CO2∼Biotin als Modell lies sich zeigen, das das CO2 mit der Biotin-Molekel an einem der beiden N-Atome zu einer allophansaure-artigen Struktur verknupft ist, was schlieslich durch Synthese des Dimethyl-esters der CO2∼ Biotin-Verbindung bewiesen werden konnte.

Published
1959

27. Post-translational activation introduces a free radical into pyruvate formate-lyase.

Author

Knappe, J, Neugebauer, F A, Blaschkowski, H P, and Gänzler, M

Abstract

Pyruvate formate-lyase (formate acetyltransferase; EC 2.3.1.54) of Escherichia coli cells is post-translationally interconverted between inactive and active forms. Conversion of the inactive to the active form is catalyzed by an Fe2+-dependent activating enzyme and requires adenosylmethionine and dihydroflavodoxin. This process is shown here to introduce a paramagnetic moiety into the structure of pyruvate formate-lyase. It displays an EPR signal at g = 2 with a doublet splitting of 1.5 mT and could comprise an organic free radical located on an amino acid residue of the polypeptide chain. Hypophosphite was discovered as a specific reagent that destroys both the enzyme radical and the enzyme activity; it becomes covalently bound to the protein. The enzymatic generation of the radical, which is linked to adenosylmethionine cleavage into 5'-deoxyadenosine and methionine, possibly occurs through an Fe-adenosyl complex. These results suggest a radical mechanism for the catalytic cycle of pyruvate formate-lyase.

Published
1984
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28. Reconstitution and characterization of the polynuclear iron-sulfur cluster in pyruvate formate-lyase-activating enzyme. Molecular properties of the holoenzyme form.

Author

Külzer, R, Pils, T, Kappl, R, Hüttermann, J, and Knappe, J

Abstract

The glycyl radical (Gly-734) contained in the active form of pyruvate formate-lyase (PFL) of Escherichia coli is generated by the S-adenosylmethionine-dependent pyruvate formate-lyase-activating enzyme (PFL activase). A 5'-deoxyadenosyl radical intermediate produced by the activase has been suggested as the species that abstracts the pro-S hydrogen of the glycine 734 residue in PFL (Frey, M., Rothe, M., Wagner, A. F. V., and Knappe, J. (1994) J. Biol. Chem. 269, 12432-12437). To enable mechanistic investigations of this system we have worked out a convenient large scale preparation of functionally competent PFL activase from its apoform. The previously inferred metallic cofactor was identified as redox-interconvertible polynuclear iron-sulfur cluster, most probably of the [4Fe-4S] type, according to UV-visible and EPR spectroscopic information. Cys --> Ser replacements by site-directed mutagenesis determined Cys-29, Cys-33, and Cys-36 to be essential to yield active holoenzyme. Gel filtration chromatography showed a monomeric structure (28 kDa) for both the apoenzyme and holoenzyme form. The iron-sulfur cluster complement proved to be a prerequisite for effective binding of adenosylmethionine, which induces a characteristic shift of the EPR signal shape of the reduced enzyme form ([4Fe-4S]+) from axial to rhombic symmetry.

Published
1998

29. On sudden death

Author

Mazur Na, Cobb La, Chamberlain Da, Mogensen L, Janse Mj, Hay Dr, Rautaharju P, Knappe J, Pyörälä K, and Harwood A

Subjects
medicine.medical_specialty, Death, Sudden, Nuclear warfare, business.industry, International Cooperation, Emergency medicine, Medicine, Humans, Cardiology and Cardiovascular Medicine, business, Sudden death, Nuclear Warfare
Published
1984

42. Zum Mechanismus der Phosphoketolasereaktion

Author

Holzer, H., Schröter, W., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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43. Structure and Activity of Flavoproteins of the Respiratory Chain

Author

Veeger, C., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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44. Struktur und Wirkungsweise NAD-abhängiger Dehydrogenasen

Author

Sund, Horst, Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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45. The catalytic site and mechanism of action of bovine pancreatic ribonuclease

Author

Rabin, B. R., Mathias, A. P., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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46. Über die Produkt- und Substratstereospezifizität der enzymatischen Reduktion von Carbonyl-Verbindungen

Author

Prelog, V., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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48. Gruppenübertragung als chemische Reaktion (gezeigt am Beispiel der Einkohlenstoff-Reaktionen)

Author

Jaenicke, L., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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49. Die Koordinationschemie der Flavokoenzyme und die Bedeutung der Nicht-Häm-Metallionen in der Atmungskette

Author

Hemmerich, Peter, Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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50. The synthesis of ADP and ATP via the oxidation of quinol phosphates

Author

Clark, V. M., Wieland, Th., Wallenfels, Kurt, Streffer, Christian, Bender, Myron L., Fasold, H., Gröschel-Stewart, U., Gundlach, G., Turba, F., Rabin, B. R., Mathias, A. P., Witzel, Herbert, Veeger, C., Hemmerich, Peter, Jaenicke, L., Kohlhaw, G., Holzer, H., Schröter, W., Knappe, J., Lynen, F., Clark, V. M., Prelog, V., Pfleiderer, G., and Sund, Horst

Published
1964
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