scholarly journals Structure-function analysis of murine interleukin 1: biologically active polypeptides are at least 127 amino acids long and are derived from the carboxyl terminus of a 270-amino acid precursor.

1986 ◽  
Vol 83 (21) ◽  
pp. 8303-8307 ◽  
Author(s):  
T. M. DeChiara ◽  
D. Young ◽  
R. Semionow ◽  
A. S. Stern ◽  
C. Batula-Bernardo ◽  
...  
1987 ◽  
Vol 252 (1) ◽  
pp. E147-E151
Author(s):  
K. D. Bloch ◽  
J. B. Zisfein ◽  
M. N. Margolies ◽  
C. J. Homcy ◽  
J. G. Seidman ◽  
...  

Proatrial natriuretic factor (proANF), the 126-amino acid precursor of ANF, is the major storage form in mammalian atria. In contrast, two ANF peptides containing the 28- and 24-carboxyterminal residues of proANF have been isolated from rat plasma. Whether the cleavage of proANF in vivo to these ANF peptides occurs during or after its release into the circulation has not been determined. The latter possibility was suggested by our previous study where, by using a cultured rat cardiocyte preparation, we demonstrated that proANF is secreted intact into the culture medium. We now report that serum, but not plasma, contains a protease that specifically cleaves the 17-kdalton proANF to a 14-kdalton amino-terminal peptide and the carboxyterminal 3-kdalton circulating forms of ANF. The role of this proANF-cleaving enzyme in the generation of the biologically active ANF peptides remains to be defined. Its isolation and characterization should provide insights into its site of production and whether in vivo it is involved in the processing of circulating proANF.


1999 ◽  
Vol 65 (6) ◽  
pp. 2281-2286 ◽  
Author(s):  
Bibek Ray ◽  
Robin Schamber ◽  
Kurt W. Miller

ABSTRACT The properties of the pediocin AcH precursor, prepediocin AcH, have been studied to gain insight into how producer cells may protect themselves from the activity of intracellular prebacteriocins. The native 62-amino-acid precursor and the 44-amino-acid mature species were expressed in Escherichia coli host strains that lack the leader peptide processing enzyme, PapD. Both forms inhibited the growth of the test bacterium Listeria innocua Lin11, indicating that the native precursor is biologically active. The two species also were synthesized in the context of maltose-binding protein chimeric proteins to facilitate the measurement of their relative specific activities. The chimeric form of the precursor was ∼80% as active as the chimeric mature species. Of relevance to cell protection and pediocin AcH production, it was determined that the precursor is strongly susceptible to inactivation by reducing agents and to degradation by chymotrypsin and endogenous E. coliproteases. Taken together, the results indicate that the activity of prepediocin AcH may have to be controlled prior to secretion to prevent toxicity to the host. Perhaps producer cells avoid membrane damage by maintaining the precursor in a reduced inactive state or by degrading molecules whose secretion is delayed.


1988 ◽  
Vol 8 (3) ◽  
pp. 1247-1252 ◽  
Author(s):  
E Lazar ◽  
S Watanabe ◽  
S Dalton ◽  
M B Sporn

To study the relationship between the primary structure of transforming growth factor alpha (TGF-alpha) and some of its functional properties (competition with epidermal growth factor (EGF) for binding to the EGF receptor and induction of anchorage-independent growth), we introduced single amino acid mutations into the sequence for the fully processed, 50-amino-acid human TGF-alpha. The wild-type and mutant proteins were expressed in a vector by using a yeast alpha mating pheromone promoter. Mutations of two amino acids that are conserved in the family of the EGF-like peptides and are located in the carboxy-terminal part of TGF-alpha resulted in different biological effects. When aspartic acid 47 was mutated to alanine or asparagine, biological activity was retained; in contrast, substitutions of this residue with serine or glutamic acid generated mutants with reduced binding and colony-forming capacities. When leucine 48 was mutated to alanine, a complete loss of binding and colony-forming abilities resulted; mutation of leucine 48 to isoleucine or methionine resulted in very low activities. Our data suggest that these two adjacent conserved amino acids in positions 47 and 48 play different roles in defining the structure and/or biological activity of TGF-alpha and that the carboxy terminus of TGF-alpha is involved in interactions with cellular TGF-alpha receptors. The side chain of leucine 48 appears to be crucial either indirectly in determining the biologically active conformation of TGF-alpha or directly in the molecular recognition of TGF-alpha by its receptor.


2004 ◽  
Vol 91 (01) ◽  
pp. 38-42 ◽  
Author(s):  
Christof Geisen ◽  
Erhard Seifried ◽  
Johannes Oldenburg ◽  
Matthias Watzka

SummaryFactorVIII acts as an essential compound of the tenase complex of the coagulation system. Herein we report the cDNA of the rat factor VIII. The rat cDNA comprises 6777 nucleotides and encodes a protein of 2258 amino acids, 61 amino acids less than mouse and 92 amino acids less than human factor VIII. The overall identity compared to human cDNA is 61% on the cDNA and 51% on the amino acid level. In cDNA, highest levels of sequence identity can be observed in the A and C domains (ranging between 68% and 73%), whereas B domain and the small acidic regions are more divergent (34%-49%). Compared to mouse and human most sites for posttranslational modifications such as sulfatation and glycosylation as well as thrombin and protein C cleavage sites are conserved in rat. Alternative transcripts lacking exon 17 and/or comprising additional 26 bp due to alternative splicing of exon 20 were found. Furthermore, 13 polymorphisms (seven in exon 14, one in exon 20, 23, 24, and 25, two in the 3’UTR) three of which lead to an amino acid exchange could be detected. Our findings might provide new insights into the structure-function analysis of the factor VIII protein and might prove useful for future animal models addressing the function of factor VIII.


2021 ◽  
pp. 219-225
Author(s):  
Галина Табаленкова

The results of studies of the qualitative composition and quantitative content of amino acids (AAs) in the leaves of three plant species of the genus Artemisia, widespread in the Elton region, were presented. Protein AAs were determined on an AAA T-339 amino acid analyzer (Czech Republic) after hydrolysis of a sample in 6N HCl at 105 °C for 24 h, free AAs – on an AAA-400 amino acid analyzer (Czech Republic) in a lithium buffer system. The protein AAs amount varied from 66 mg / g in A. lerchiana to 113 mg / g dry weight in A. santonica. 17 AAs were found in composition of these species, aspartic and glutamic acids were dominant. The content of free AAs varied from 4.4 mg / g in A. santonica to 8.3 mg / g dry weight in A. pauciflora. 14 AAs have been identified, among them proline was the predominant free AA. The share of proline was 75-81% of the total free AAs. Among the minor components, 3-4 compounds with a content above 2% dominated. The free AAs contain 3 non-proteinogenic ones (ornithine, citruline, and γ-aminobutyric acid). A. lerchiana and A. pauciflora species were similar in protein and free amino acids, probably due to the same growing conditions. A high level of free proline, together with a complex of biologically active substances in Artemisia species, which grow abundantly in the Elton region, allow to consider the possibility of their use as a medicinal raw material.


1997 ◽  
Vol 17 (1) ◽  
pp. 115-122 ◽  
Author(s):  
M B Sainz ◽  
S A Goff ◽  
V L Chandler

C1 is a transcriptional activator of genes encoding biosynthetic enzymes of the maize anthocyanin pigment pathway. C1 has an amino terminus homologous to Myb DNA-binding domains and an acidic carboxyl terminus that is a transcriptional activation domain in maize and yeast cells. To identify amino acids critical for transcriptional activation, an extensive random mutagenesis of the C1 carboxyl terminus was done. The C1 activation domain is remarkably tolerant of amino acid substitutions, as changes at 34 residues had little or no effect on transcriptional activity. These changes include introduction of helix-incompatible amino acids throughout the C1 activation domain and alteration of most single acidic amino acids, suggesting that a previously postulated amphipathic alpha-helix is not required for activation. Substitutions at two positions revealed amino acids important for transcriptional activation. Replacement of leucine 253 with a proline or glutamine resulted in approximately 10% of wild-type transcriptional activation. Leucine 253 is in a region of C1 in which several hydrophobic residues align with residues important for transcriptional activation by the herpes simplex virus VP16 protein. However, changes at all other hydrophobic residues in C1 indicate that none are critical for C1 transcriptional activation. The other important amino acid in C1 is aspartate 262, as a change to valine resulted in only 24% of wild-type transcriptional activation. Comparison of our C1 results with those from VP16 reveal substantial differences in which amino acids are required for transcriptional activation in vivo by these two acidic activation domains.


1996 ◽  
Vol 16 (3) ◽  
pp. 1103-1114 ◽  
Author(s):  
S Govind ◽  
E Drier ◽  
L H Huang ◽  
R Steward

The formation of a gradient of nuclear Dorsal protein in the early Drosophila embryo is the last step in a maternally encoded dorsal-ventral signal transduction pathway. This gradient is formed in response to a ventral signal, which leads to the dissociation of cytoplasmic Dorsal from the I kappa B homolog Cactus. Free Dorsal is then targeted to the nucleus. Dorsal is a Rel-family transcription factor. Signal-dependent nuclear localization characterizes the regulation of Rel proteins. In order to identify regions of Dorsal that are essential for its homodimerization, nuclear targeting, and interaction with Cactus, we have performed an in vivo structure-function analysis. Our results show that all these functions are carried out by regions within the conserved Rel-homology region of Dorsal. The C-terminal divergent half of Dorsal is dispensable for its selective nuclear import. A basic stretch of 6 amino acids at the C terminus of the Rel-homology region is necessary for nuclear localization. This nuclear localization signal is not required for Cactus binding. Removal of the N-terminal 40 amino acids abolished the nuclear import of Dorsal, uncovering a potentially novel function for this highly conserved region.


Author(s):  
Toshio Iwasaki ◽  
Yoshiharu Miyajima-Nakano ◽  
Risako Fukazawa ◽  
Myat T Lin ◽  
Shin-Ichi Matsushita ◽  
...  

Abstract A set of C43(DE3) and BL21(DE3) Escherichia coli host strains that are auxotrophic for various amino acids is briefly reviewed. These strains require the addition of a defined set of one or more amino acids in the growth medium, and have been specifically designed for overproduction of membrane or water-soluble proteins selectively labeled with stable isotopes such as 2H, 13C and 15N. The strains described here are available for use and have been deposited into public strain banks. Although they cannot fully eliminate the possibility of isotope dilution and mixing, metabolic scrambling of the different amino acid types can be minimized through a careful consideration of the bacterial metabolic pathways. The use of a suitable auxotrophic expression host strain with an appropriately isotopically labeled growth medium ensures high levels of isotope labeling efficiency as well as selectivity for providing deeper insight into protein structure-function relationships.


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