Synthesis of a Biologically Active Nonadecapeptide Corresponding to the First Nineteen Amino Acid Residues of Adrenocorticotropins1a

1961 ◽  
Vol 83 (21) ◽  
pp. 4449-4457 ◽  
Author(s):  
Choh Hao Li ◽  
Johannes Meienhofer ◽  
Eugen Schnabel ◽  
David Chung ◽  
Tung-Bin Lo ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biologically Active ◽  
Amino Acid Residues

Analogues of the cholecystokinin octapeptide modified in the central part of the molecule

1991 ◽  
Vol 56 (9) ◽  
pp. 1963-1970 ◽  
Author(s):  
Jan Hlaváček ◽  
Václav Čeřovský ◽  
Jana Pírková ◽  
Pavel Majer ◽  
Lenka Maletínská ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Point Of View ◽  
Biologically Active ◽  
Side Chain ◽  
Amino Acid Residues ◽  
Cholecystokinin Octapeptide ◽  
Biological Tests ◽  
Biological Potency ◽  
Biologically Active Conformation

In a series of analogues of the cholecystokinin octapeptide (CCK-8) the amino acid residues were gradually modified by substituting Gly by Pro in position 4, Trp by His in position 5, Met by Cle in position 6, or the Gly residue was inserted between Tyr and Met in positions 2 and 3 of the peptide chain, and in the case of the cholecystokinin heptapeptide (CCK-7) the Met residues were substituted by Nle or Aib. These peptides were investigated from the point of view of their biological potency in the peripheral and central region. From the results of the biological tests it follows that the modifications carried out in these analogues and in their Nα-Boc derivatives mean a suppression of the investigated biological activities by 2-3 orders of magnitude (at a maximum dose of the tested substance of 2 . 10-2 mg per animal).This means that a disturbance of the assumed biologically active conformation of CCK-8, connected with a considerable decrease of the biological potency of the molecule, takes place not only after introduction of the side chain into its centre (substitution of Gly4), but also after the modification of the side chains of the amino acids or by extension of the backbone in further positions around this central amino acid.

scholarly journals Primary Structure Analysis of Antifungal Peptides from Cultivated and Wild Cereals

Plants ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 74 ◽  
Author(s):  
Eugene Rogozhin ◽  
Dmitry Ryazantsev ◽  
Alexey Smirnov ◽  
Sergey Zavriev
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Antifungal Activity ◽  
Antimicrobial Peptides ◽  
Structure Analysis ◽  
Primary Structure ◽  
Biologically Active ◽  
Amino Acid Residues ◽  
Wild Cereals ◽  
Determining Factor

Cereal-derived bioactive peptides with antimicrobial activity have been poorly explored compared to those from dicotyledonous plants. Furthermore, there are a few reports addressing the structural differences between antimicrobial peptides (AMPs) from cultivated and wild cereals, which may shed light on significant varieties in the range and level of their antimicrobial activity. We performed a primary structure analysis of some antimicrobial peptides from wild and cultivated cereals to find out the features that are associated with the much higher antimicrobial resistance characteristic of wild plants. In this review, we identified and analyzed the main parameters determining significant antifungal activity. They relate to a high variability level in the sequences of C-terminal fragments and a high content of hydrophobic amino acid residues in the biologically active defensins in wild cereals, in contrast to AMPs from cultivated forms that usually exhibit weak, if any, activity. We analyzed the similarity of various physicochemical parameters between thionins and defensins. The presence of a high divergence on a fixed part of any polypeptide that is close to defensins could be a determining factor. For all of the currently known hevein-like peptides of cereals, we can say that the determining factor in this regard is the structure of the chitin-binding domain, and in particular, amino acid residues that are not directly involved in intermolecular interaction with chitin. The analysis of amino acid sequences of alpha-hairpinins (hairpin-like peptides) demonstrated much higher antifungal activity and more specificity of the peptides from wild cereals compared with those from wheat and corn, which may be associated with the presence of a mini cluster of positively charged amino acid residues. In addition, at least one hydrophobic residue may be responsible for binding to the components of fungal cell membranes.

Bovine growth hormone fragment (1–133) has in-vitro somatomedin-like activity

1983 ◽  
Vol 96 (2) ◽  
pp. 195-199 ◽  
Author(s):  
J. P. Liberti ◽  
L. A. Durham
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Costal Cartilage ◽  
Peptide Bond ◽  
Biologically Active ◽  
The Other ◽  
Bovine Growth Hormone ◽  
Amino Acid Residues ◽  
In Vitro Uptake

Thrombin digestion of bovine growth hormone (1–191) resulted in cleavage of the peptide bond between amino acid residues 133 and 134. Native growth hormone and purified peptides (1–133) and (134–191) were assayed for somatomedin-like activity. Peptide (1–133), ranging in concentration from 0·15–15 nmol/l, stimulated in-vitro uptake of [3H]thymidine by rat costal cartilage. None of the other peptides was biologically active.

scholarly journals The aminoacylation of transfer ribonucleic acid. Inhibitory effects of some amino acid analogues with altered side chains

1976 ◽  
Vol 159 (3) ◽  
pp. 503-511 ◽  
Author(s):  
J M Old ◽  
D S Jones
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Structural Features ◽  
Biologically Active ◽  
Side Chains ◽  
Amino Acid Residues ◽  
Trna Synthetases ◽  
E Coli ◽  
Amino Acid Side Chains ◽  
Amino Acid Analogues

Several amino acid analogues that are able to replace amino acid residues in binding positions of the biologically active C-terminal tetrapeptide amide sequence, Trp-Met-Asp-PheNH2, of the gastrins were examined for their ability to inhibit the aminoacylation of tRNA in an Escherichia coli and rat liver system. Although in both systems the amino acid side chains are involved in the recognition process, the structural requirements of the side chain in the two systems are not comparable. Analogues of methionine and phenylalanine behaved similarly in the E. coli and rat liver systems, whereas analogues of tryptophan behaved differently. From the results it is possible to suggest structural features of the amino acid side chains which are required for recognition by the aminoacyl-tRNA synthetases.

Stimulation of gonadotropin release by a non-GnRH peptide sequence of the GnRH precursor

Science ◽  
1986 ◽  
Vol 232 (4746) ◽  
pp. 68-70 ◽  
Author(s):  
RP Millar ◽  
PJ Wormald ◽  
RC Milton
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Basic Amino Acid ◽  
Prolactin Secretion ◽  
Biologically Active ◽  
Peptide Sequence ◽  
Pituitary Cells ◽  
Amino Acid Residues ◽  
Amino Acid Peptide ◽  
Gonadotropin Release

The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture. The peptide did not affect thyrotropin or prolactin secretion. A GnRH antagonist did not inhibit gonadotropin stimulation by the peptide, and the peptide did not compete with GnRH for GnRH pituitary receptors, indicating that the action of the peptide is independent of the GnRH receptor. The GnRH precursor contains two distinct peptide sequences capable of stimulating gonadotropin release from human and baboon pituitary cells.

scholarly journals Human ciliary neurotrophic factor: a structure-function analysis

1995 ◽  
Vol 309 (1) ◽  
pp. 215-220 ◽  
Author(s):  
A Krüttgen ◽  
J Grötzinger ◽  
G Kurapkat ◽  
J Weis ◽  
R Simon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Neurotrophic Factor ◽  
Rational Design ◽  
Function Analysis ◽  
Three Dimensional ◽  
Ciliary Neurotrophic Factor ◽  
Biologically Active ◽  
Leukaemia Inhibitory Factor ◽  
Amino Acid Residues ◽  
C Terminus

Ciliary neurotrophic factor (CNTF) promotes survival in vitro and in vivo of several neuronal cell types including sensory and motor neurons. The primary structure of CNTF suggests it to be a cytosolic protein with strong similarity to the alpha-helical cytokine family which is characterized by a bundle of four anti-parallel helices. CNTF exerts its activity via complexation with CNTF receptor (CNTF-R). This complex consists of a CNTF-binding protein (CNTF-R) and two proteins important for signal transduction [gp130 and leukaemia inhibitory factor receptor (LIF-R)]. We have shortened the cDNA coding for CNTF at both the 5′ and the 3′ end and expressed the truncated proteins in bacteria. Biological activities of the protein preparations were determined by their ability to induce proliferation of BAF/3 cells that were stably transfected with CNTF-R, gp130 and LIF-R cDNAs. CNTF proteins with 14 amino acid residues removed from the N-terminus were biologically active whereas the removal of 23 amino acids resulted in an inactive protein. In addition, 18 amino acid residues could be removed from the C-terminus of the CNTF protein without apparent loss of bioactivity, but further truncation at the C-terminus yielded biologically inactive proteins. The introduction of two point mutations into the CNTF protein at a site that presumably interacts with one of the two signal-transducing proteins resulted in a CNTF mutant with no measurable bioactivity. In addition, a model of the three-dimensional structure of human CNTF was constructed using the recently established structural co-ordinates of the related cytokine, granulocyte colony-stimulating factor. CD spectra of CNTF together with our mutational analysis and our three-dimensional model fully support the view that CNTF belongs to the family of alpha-helical cytokines. It is expected that our results will facilitate the rational design of CNTF mutants with agonistic or antagonistic properties.

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