Amino acids and peptides. XXXVIII. Structural analogues of oxytocin modified in position 2 of the peptide chain: Preparation and some chemical and biological properties

1963 ◽  
Vol 28 (7) ◽  
pp. 1706-1714 ◽  
Author(s):  
K. Jošt ◽  
J. Rudinger ◽  
F. Šorm
Keyword(s):  
Amino Acids ◽  
Biological Properties ◽  
Peptide Chain ◽  
Structural Analogues

Bio-organometallic Peptide Conjugates: Recent Advances in Their Synthesis and Prospects for Biomedical Application

2020 ◽  
Vol 24 (21) ◽  
pp. 2508-2523
Author(s):  
Johana Gómez ◽  
Diego Sierra ◽  
Constanza Cárdenas ◽  
Fanny Guzmán
Keyword(s):  
Amino Acids ◽  
Biomedical Application ◽  
Structural Diversity ◽  
Biological Properties ◽  
Therapeutic Agents ◽  
Organometallic Complexes ◽  
Chemical Behavior ◽  
Metal Compounds ◽  
Bioorganometallic Chemistry ◽  
Pharmacological Control

One area of organometallic chemistry that has attracted great interest in recent years is the syntheses, characterization and study of organometallic complexes conjugated to biomolecules with different steric and electronic properties as potential therapeutic agents against cancer and malaria, as antibiotics and as radiopharmaceuticals. This minireview focuses on the unique structural diversity that has recently been discovered in α- amino acids and the reactions of metallocene complexes with peptides having different chemical behavior and potential medical applications. Replacing α-amino acids with metallocene fragments is an effective way of selectively influencing the physicochemical, structural, electrochemical and biological properties of the peptides. Consequently, research in the field of bioorganometallic chemistry offers the opportunity to develop bioactive metal compounds as an innovative and promising approach in the search for pharmacological control of different diseases.

The C-terminal sequence of amino acid residues of κ-casein isolated from buffalo's milk

1967 ◽  
Vol 34 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. H. Abd El-Salam ◽  
W. Manson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Peptide Chain ◽  
Amino Acid Residues ◽  
Terminal Sequence ◽  
Carboxypeptidase A ◽  
Phosphorous Content ◽  
Single Peptide

SummaryWhen κ-casein from buffalo's milk was treated with carboxypeptidase A (EC 3. 4. 2. 1),4 amino acids, valine, threonine, serine and alanine were released from the protein in a manner consistent with the view that they originate in the C-terminal sequence of a single peptide chain. The amounts produced suggest a minimum molecular weight for buffalo κ-casein of approximately 17000, in agreement with the value calculated from the phosphorous content on the basis of the presence of 2 phosphorus atoms/molecule. A comparison is made with the C-terminal sequence reported for bovine κ-casein.

scholarly journals The Efficient Synthesis of Azasugars from Pentoses

2021 ◽  
Author(s):  
◽  
Michael Meijlink
Keyword(s):  
Clinical Trials ◽  
Biological Properties ◽  
Protecting Groups ◽  
Synthetic Route ◽  
Efficient Synthesis ◽  
Atom Economy ◽  
Total Syntheses ◽  
Structural Analogues ◽  
Original Procedure ◽  
Synthetic Routes

<p>Azasugars [e.g., 1-deoxy-aza-xylopyranose (1) Figure 1] are structural analogues of sugars [e.g., α-D-xylopyranose (2)] where the ring oxygen is substituted by a nitrogen atom. The resemblance of azasugars to their carbohydrate counterparts gives them various biological properties, such as the inhibition of glycosidase and glycosyltransferase enzymes, and as such, these compounds have been in clinical trials for the treatment of AIDS, diabetes,and cancer. Synthetic routes to azasugars have often involved the use of protecting groups, and therefore have generally reduced efficiency by requiring additional steps to apply or remove protecting groups or requiring adjustment of stereochemistry during the synthesis. This thesis presents the first example of a synthesis of four sterochemically different piperidine triols through a four-step methodology minimising the use of protecting groups starting from pentoses. The synthesis of D-xylose derived (3R,4r,5S)-piperidine triol was previously obtained in 40% yield over five steps, but was afforded in 45% overall yield over four steps using the methodology described within this thesis. Next, D-ribose derived (3R,4s,5S)-piperidine triol was obtained in 40% overall yield over four steps, which afforded a vast improvement on the previous most efficient synthetic route obtaining the azasugar in 24% yield over four steps. This four-step three-pot methodology has thus allowed for the synthesis of these piperidine triols in overall yields ranging from 4-69%, surpassing previous total syntheses in efficiency and improving overall atom economy. To further probe the applicability of the methodology, N-alkyl analogues (such as butyl-, phenylethyl-, and hydroxyethyl-analogues) of all four different piperidine triols were synthesised in comparable or greater overall yields compared to literature reports without any required adaptation to the original procedure. Included in these N-alkyl analogues are seven novel azasugars which were obtained in overall yields ranging from 6-35%.</p>

scholarly journals The functional importance of the extreme C-terminal tail in the gene 2 organellar Ca2+-transport ATPase (SERCA2a/b)

1994 ◽  
Vol 303 (3) ◽  
pp. 979-984 ◽  
Author(s):  
H Verboomen ◽  
F Wuytack ◽  
L Van den Bosch ◽  
L Mertens ◽  
R Casteels
Keyword(s):  
Amino Acids ◽  
Splice Variant ◽  
Turnover Rate ◽  
Peptide Chain ◽  
Deletion Mutants ◽  
Functional Difference ◽  
Critical Importance ◽  
Transmembrane Segment ◽  
Functional Importance ◽  
Transport Atpase

Ca(2+)-uptake experiments in microsomal fractions from transfected COS-1 cells have revealed a functional difference between the non-muscle SERCA2b Ca2+ pump and its muscle-specific SERCA2a splice variant. Structurally, the two pumps differ only in their C-terminal tail. The last four amino acids of SERCA2a are replaced in SERCA2b by a 49-residue-long peptide chain containing a very hydrophobic stretch which could be an additional transmembrane segment. The functionally important subdomains in the SERCA2b tail were analysed by constructing three SERCA2b deletion mutants lacking 12, 31 or 49 amino acids. The mutants and the parental SERCA2 pumps were expressed in COS-1 cells and analysed for functional difference. SERCA2b had a twofold higher Ca2+ affinity, a twofold lower turnover rate and a 10-fold lower vanadate-sensitivity than SERCA2a and the mutants. Since each of the three truncated versions of SERCA2b acquire the characteristic properties of SERCA2a, it is concluded that the stretch of the last 12 residues of SERCA2b is of critical importance.

CHEMICAL AND BIOLOGICAL PROPERTIES OF CULTURE FILTRATES OF WESTIELLOPSIS PROLIFICA AND CHAETOPHORA ATTENUATA

1996 ◽  
Vol 44 (1) ◽  
pp. 43-48 ◽  
Author(s):  
S.C. Agrawal ◽  
U.K. Sharma
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Free Amino ◽  
Biological Properties ◽  
Total Chlorophyll ◽  
Total Chlorophyll Content ◽  
Westiellopsis Prolifica ◽  
Total Free Amino Acids ◽  
Zoospore Formation ◽  
Growth And Reproduction

Westiellopsis prolifica Janet and Chaetophora attenuata Hazen cultures released sugars (glucose, fructose, and sucrose), organic acids (oxaloacetic acid and oxalic acid), amino acids, and protein. W. prolifica cultures released the amino acids glycine, serine, cystine, glutamic acid, aspartic acid, and α-alanine, while C. attenuata cultures released glycine, serine, aspartic acid, and α-alanine. W. prolifica and C. attenuata cultures of all ages released more extracellular protein than total free amino acids. Cultures of C. attenuata released more protein than cultures of the same age of W. prolifica. The filtrates from old cultures of W. prolifica and C. attenuata decreased the total chlorophyll content of all algae tested, totally suppressed conjugation in Spirogyra decimino and zoospore formation in C. attenuata, and drastically decreased spore germination in W. prolifica, thus producing stressful conditions affecting the growth and reproduction of these and other algae.

scholarly journals Wachstumsgeschwindigkeit der Peptidkette im Tabakmosaikvirus

1967 ◽  
Vol 22 (12) ◽  
pp. 1280-1291 ◽  
Author(s):  
H. Diringer ◽  
F. A. Anderer ◽  
G. Schramm
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Protein Synthesis ◽  
Peptide Chain ◽  
Cell Protein ◽  
Virus Protein ◽  
Animal Cells ◽  
Tobacco Leaves ◽  
Soluble Cell ◽  
C Terminus

The rate of incorporation of labelled amino acids into the complete tobacco mosaic virus (TMV), into soluble virus protein and into soluble cell proteins has been determined in discs of infected and healthy tobacco leaves. The rate of overall protein synthesis is increased by 50% in the infected leaves. At least 60% of the increase derives from the synthesis of virus-specific proteins and the synthesis of cellular proteins is not inhibited. The virus protein synthesis is strongly temperature dependent and shows a maximum at 28 °C.The exchange of free labelled amino acids between the external medium and the inner cellular pool reaches equilibrium within ten minutes. The influence of the exchange rate on the measurement of the kinetics of peptide chain synthesis is discussed in detail.Discs from infected leaves were incubated for short periods at low temperatures in media containing 3H-tyrosine or 3H-proline. Peptides isolated after 5 minutes incubation at 15 °C were found to be uniformly labelled with no apparent gradient of radioactivity from the N- to the C-terminus. The results indicate that the growth rate of the peptide chain at 15 °C is probably higher than 2 - 3 amino acids/sec and at 28 °C higher than 20 amino acids/sec. These values are higher than those for animal cells and similar to those for protein synthesis in Escherichia coli.Comparison of the growth rate of TMV protein with rate of total protein synthesis and the number of ribosomes in the tobacco leaves indicate that only a small portion of the ribosomes takes part in cell protein synthesis.

Sign in / Sign up

Export Citation Format

Share Document