Search PubMed⌕ Search

Biomedical subjects

E Schlimme

Publications and source records attributed to E Schlimme.

65 records · Page 4Linked to original sources
PubMed1968

Uber das aminoacylierungsverhalten chemisch modifizierter phenylalaninspezifischer transfer-ribonucleinsäure aus hefe: (1) Glykolspaltung und reduktion zum diol an der 3'-terminalen ribose.

The terminal cis-glycol-group of phenylalanine specific tRNA (tRNA(Phe), I) from yeast was oxidized to the dialdehyde by NaIO(4) (tRNA(Phe)(oxi), II) and subsequently reduced to the diol by NaBH(4) (tRNA(Phe)(oxi-red), III). In charging experiments it could be shown that tRNA(Phe)(oxi-red) is still completely specific for phenylalanine. The Michaelis constant of tRNA(Phe)(oxi-red) remains unchanged when compared with tRNA(Phe), while the maximun velocity of charging upsilon(max) of tRNA(Phe)(oxi-red) is decreased to about one half.

Journal Article↗
PubMedDate not supplied

P1, P5-Bis-(5'-adenosyl)pentaphosphate: is this adenylate kinase inhibitor substrate for mitochondrial processes?

1. P1, P5-Bis-(5'-adenosyl) pentaphosphate (AP5-A) inhibits "soluble" adenylate kinase even when this enzyme is an integral part of the complete mitochondrion. The Ki is 10(-5) M, i.e. about two orders of magnitude higher than the inhibitor contants determined for the purified adenylate kinase of rabbit muscle and an enzyme preparation separated from the mitochondrial intermembrane space. The weaker inhibitory effect is due to a lower accessibility of the enzyme. 2. as to be expected Ap5A which is of the "multisubstrate analogue"-type does not affect mitochondrial nucleoside diphosphate kinase. 3. Though Ap5A owns the structural elements of both ATP and ADP it is not a substrate of the adenine nucleotide carrier, i.e. neither it is exchanged across the inner mitochondrial membrane nor speicifically bound. 4. Ap5A is not metabolized by rat liver mitochondria.

Adenine Nucleotides↗
PubMedDate not supplied

Conformationally restricted adenine nucleotide analogs in mitochondrial adenine nucleotide transport.

The conformationally restricted adenine nucleotide analogs 8,3'anhydro-8-oxy-9-(beta-D-xylofuranosyl)adenine-5'-O-tri(di)-phosphate (I), and 8,2'-anhydro-8-oxy-9-(beta-D-arabinofuranosyl) adenine-5'-O-tri(di)-phosphate (II), were prepared chemically as their alpha-32P-labelled compounds and compared with syn-structured 8-bromo AT(D)P in mitochondrial adenine nucleotide translocation. The experimental findings demonstrate that the heterocycle-ribose orientation affects the carrier mediated adenine nucleotide transport very strongly, i.e. a non fixed adenine heterocycle in the anti region is prerequisite for the bound nucleotide to induce the transfer action of the adenine nucleotide carrier.

Adenine Nucleotides↗
PubMedDate not supplied

Ribonucleosides in human milk. Concentration profiles of these minor constituents as a function of the nursing time.

Ribonucleosides are secreted as products of cellular RNA and ribonucleotide metabolism into physiological fluids such as blood, milk and urine. Unmodified and modified ribonucleosides have been detected in the micromolar range as minor constituents in the milk of different mammals. In addition to the common nucleosides adenosine, cytidine, guanosine, inosine and uridine, modified components such as 1-methyladenosine, 1-methylguanosine, 1-methylinosine, N2-methylguanosine, N2-dimethylguanosine, N6-carbamoyl-L-threonyladenosine, pseudouridine and 5-aminoimidazole-4-carboxamide-N-ribofuranoside (AICAR) have been identified and most of them quantified in samples of human and/or bovine and/or goat's milk. From these investigations it is known that nucleosides, in analogy to nucleotides, show a typical species-specific pattern. Longitudinal studies have been carried out to determine the concentration profiles of the individual ribonucleosides in the milk of humans as a function of the nursing time.

Animals↗
PubMedDate not supplied

Effect of 5'-terminated (2'-5')-oligoadenylates on cap degrading activities in rat liver nuclei.

(2'-5')-oligoadenylates bearing a 5'-terminal triphosphate or a 5'GTP-group inhibit the activity of a dinucleoside triphosphatase in rat liver nuclei thereby protecting mRNA against 5'-exonucleolytic degradation. (2'-5')-oligoadenylates, on the other hand, were known to enhance the activity of an endoribonuclease, RNaseF. Thus a synergistic effect may be assumed in vivo, i.e. cellular metabolism seems to be protected twice in virus-infected cells.

Adenine Nucleotides↗
PubMedDate not supplied

[The importance of the position of the adenosine linkage in NAD+ for its coenzyme activity via lactate dehydrogenase (author's transl)].

We report on the chemical preparation of the NAD+ analog P1, P2-(5'-beta-nicotinamideribofuranosyl-3"-adenosyl)-diphosphate (N3"AD+) by applying the 1,1'-carbonyldiimidazole activation method. The importance of how adenosine is linked to the nicotinamide mononucleotide phosphoriboride (NMNPR+) moiety is discussed with respect to the coenzyme activity in the lactate dehydrogenase catalyzed reaction.

Kinetics↗
PubMedDate not supplied

[P1, P3-(5'-guanosyl-5''-[14C]adenosyl)triphosphate: preparation of the cap parent compound and its catabolic properties towards rat liver subcellular fractions (author's transl)].

We report on the chemical preparation of 14C-labeled P1, P3-(5'-guanosyl-5''-adenosyl)triphosphate (1) which is the parent compound of 5'-terminal cap structures of most eukaryotic mRNAs. Incubation experiments of cap (1)- and non cap-structured nucleotides as Ap2A (2) as well as their ribose ring opened derivatives (3, 4) with rat liver subcellular fractions show that cap-degrading nucleases being able to unblock 5' termini are present in nuclei but not in mitochondria.

Animals↗