scholarly journals Toxigenic clostridia.

1990 ◽  
Vol 3 (1) ◽  
pp. 66-98 ◽  
Author(s):  
C L Hatheway
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Amino Acid Sequences ◽  
Biologically Active ◽  
Antigenic Protein ◽  
Historical Aspects ◽  
Biochemical Characteristics ◽  
Animal Diseases ◽  
Human And Animal Diseases ◽  
Binary Toxins

Toxigenic clostridia belonging to 13 recognized species are discussed in this review. Each species or group of organisms is, in general, introduced by presenting the historical aspects of its discovery by early investigators of human and animal diseases. The diseases caused by each species or group are described and usually discussed in relation to the toxins involved in the pathology. Morphological and physiological characteristics of the organisms are described. Finally, the toxins produced by each organism are listed, with a presentation of their biological activities and physical and biochemical characteristics. The complete amino acid sequences for some are known, and some of the genes have been cloned. The term toxin is used loosely to include the various antigenic protein products of these organisms with biological and serological activities which have served as distinguishing characteristics for differentiation and classification. Some of these factors are not truly toxic and have no known role in pathogenicity. Some of the interesting factors common to more than one species or group are the following: neurotoxins, lethal toxins, lecithinases, oxygen-labile hemolysins, binary toxins, and ADP-ribosyltransferases. Problems in bacterial nomenclature and designation of biologically active factors are noted.

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.

NOT THAT RIGID MIDGETS AND NOT SO FLEXIBLE GIANTS: ON THE ABUNDANCE AND ROLES OF INTRINSIC DISORDER IN SHORT AND LONG PROTEINS

2012 ◽  
Vol 20 (04) ◽  
pp. 471-511 ◽  
Author(s):  
MARK HOWELL ◽  
RYAN GREEN ◽  
ALEXIS KILLEEN ◽  
LAMAR WEDDERBURN ◽  
VINCENT PICASCIO ◽  
...  
Keyword(s):  
Amino Acid ◽  
Intrinsically Disordered Proteins ◽  
Biological Activities ◽  
Intrinsic Disorder ◽  
Amino Acid Sequences ◽  
Disordered Proteins ◽  
Biological Functions ◽  
Intrinsically Disordered ◽  
Eukaryotic Proteins ◽  
Disordered Regions

Intrinsically disordered proteins or proteins with disordered regions are very common in nature. These proteins have numerous biological functions which are complementary to the biological activities of traditional ordered proteins. A noticeable difference in the amino acid sequences encoding long and short disordered regions was found and this difference was used in the development of length-dependent predictors of intrinsic disorder. In this study, we analyze the scaling of intrinsic disorder in eukaryotic proteins and investigate the presence of length-dependent functions attributed to proteins containing long disordered regions.

scholarly journals Coconut Carbon Dots: Progressive Large-Scale Synthesis, Detailed Biological Activities and Smart Sensing Aptitudes towards Tyrosine

Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 162
Author(s):  
Pooja Chauhan ◽  
Deepa Mundekkad ◽  
Amitava Mukherjee ◽  
Savita Chaudhary ◽  
Ahmad Umar ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carbon Dots ◽  
Large Scale ◽  
Limit Of Detection ◽  
Biological Activities ◽  
Biologically Active ◽  
Active Components ◽  
Ongoing Research ◽  
Amino Acid Sensing

In the recent era, carbon dots (C-dots) have been extensively considered as a potential tool in drug delivery analysis. However, there have been fewer reports in the literature on their application in the sensing of amino acids. As part of our ongoing research on coconut-husk-derived C-dots, we synthesized C-dots under different temperature conditions and utilized them in the field of amino acid sensing and found them to be highly selective and sensitive towards tyrosine. The detailed characterization of the prepared C-dots was carried out. The developed C-dots exhibit good values of quantum yield. BSA, HSA and glutamic acid were utilized to explore the binding efficiency of C-dots with biologically active components. Hemolysis, blood clotting index activity and cell viability assays using the prepared C-dots were evaluated and they were found to be biocompatible. Therefore, the C-dots described in this work have high potential to be utilized in the field of amino acid sensing, especially L-tyrosine. The limit of detection and the binding constant for the developed C-dots in the presence of tyrosine were found to be 0.96 nM and 296.38 nM−1, respectively. The efficiency of the developed C-dots was also investigated in the presence of various other amino acids and different water mediums in order to enhance the working scope of the developed sensors.

Cloning, sequencing and expression of stem cell factor (c-kit ligand) cDNA of brushtail possum (Trichosurus vulpecula)

1996 ◽  
Vol 8 (4) ◽  
pp. 789 ◽  
Author(s):  
PJ Greenwood ◽  
C Seamer ◽  
DJ Tisdall
Keyword(s):  
Stem Cell ◽  
Amino Acid ◽  
Stem Cell Factor ◽  
Biological Activities ◽  
Amino Acid Level ◽  
Amino Acid Sequences ◽  
Northern Analysis ◽  
Nucleotide Sequencing ◽  
Brushtail Possum ◽  
Factor C

By means of reverse transcription polymerase chain reaction (RT-PCR), three stem cell factor (SCF) cDNAs (822-738 bp in size) were amplified from brushtail possum ovarian poly (A)+ RNA. The largest and smallest of these cDNAs were cloned and sequenced. Characterization of these cDNAs has revealed that possum SCF has approximately 75% and 66% homology to SCF of eutherian mammals at the nucleotide level and the predicted amino acid level respectively. Nucleotide sequencing shows that the 738-bp cDNA represents an mRNA splice variant, equivalent to that found in eutherian mammals, in which an exon (84 bp) encoding a potential proteolytic cleavage site is removed. Comparison of the predicted possum SCF amino acid sequence with the predicted SCF amino acid sequences from eutherian mammals reveals conservation of all cysteine residues and 3 of 4 potential N-linked glycosylation sites. In addition, the hydropathicity profile of the possum SCF protein is similar to that of eutherian SCF suggesting that protein conformation is conserved. Northern analysis was used to characterize possum SCF gene expression in adult ovary and testis. A major transcript of 9 kb was observed in both ovarian and testicular tissue. The conservation of the SCF gene and its predicted protein, suggests that SCF in the possum has similar biological activities to SCF in eutherian mammals.

scholarly journals Amino acid sequence and molecular modelling of glycoprotein IIb-IIIa and fibronectin receptor iso-antagonists from Trimeresurus elegans venom

1996 ◽  
Vol 319 (3) ◽  
pp. 775-782 ◽  
Author(s):  
Andrea SCALONI ◽  
Elisabetta DI MARTINO ◽  
Nadia MIRAGLIA ◽  
Alessandra PELAGALLI ◽  
Rossella DELLA MORTE ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Modelling ◽  
Membrane Filtration ◽  
Platelet Rich Plasma ◽  
Biological Activities ◽  
Amino Acid Sequences ◽  
Proteolytic Processing ◽  
Fibronectin Receptor ◽  
Induced Aggregation

Low-molecular-mass Arg-Gly-Asp (RGD)-containing polypeptides were isolated from the venom of Trimeresurus elegans by a simple two-step procedure consisting of membrane filtration and reverse-phase HPLC. A combination of electrospray MS, fast-atom bombardment MS and Edman degradation allowed us to ascertain the presence in the venom of different isoforms and to determine their primary structures. The amino acid sequences resembled the structure of elegantin, the only disintegrin previously reported from the T. elegans venom [Williams, Rucinski, Holt and Niewiarowski (1990) Biochim. Biophys. Acta 1039, 81–89]. MS analyses indicated the occurrence of differential proteolytic processing at both the N-terminus and the C-terminus of the polypeptide chains. The amino acid sequence alignment of the elegantin isoforms with known components of the disintegrin family demonstrated the complete conservation of the 12 cysteine residues involved in disulphide bridges. Molecular modelling of elegantins predicted an overall folding of these molecules quite similar to that reported for the kistrin solution structure. The newly identified polypeptide isoforms strongly inhibited ADP-induced aggregation in both human and canine platelet-rich plasma but showed a different species-dependent specificity. These molecules were also able to inhibit B16-BL6 murine melanoma cell adhesion to immobilized fibronectin. The comparison of the structures and biological activities of elegantin isoforms and kistrin allowed us to highlight some structural features that, in addition to the RGD locus, might be involved in the interaction of these snake-venom polypeptides with the integrin receptors on the platelet and cell surface.

scholarly journals A bioinformatics approach for identifying the probable cause of the cross-interaction of antibodies to the antigenic protein HPV16 L1 with the HPV6 L1 protein

2021 ◽  
Vol 25 (7) ◽  
pp. 787-792
Author(s):  
A. S. Stolbikov ◽  
R. K. Salyaev ◽  
N. I. Rekoslavskaya
Keyword(s):  
T Cells ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
B Cell ◽  
Antigenic Determinant ◽  
Amino Acid Sequences ◽  
Antigenic Determinants ◽  
Antigenic Protein ◽  
Hpv Types ◽  
The Cross

This paper describes an attempt to analyze, with the aid of bioinformatics resources (programs and databases), the probable cause of the cross-interaction of antibodies against HPV16 L1 with antigenic protein HPV6 L1, which has been revealed in the investigation of the candidate vaccine obtained on the base of a plant expression system (tomato plants). In our opinion, the most likely reason for the cross-interaction of antibodies with antigens of different pathogenic HPV types is the similarity of their antigenic determinants. In this work, the amino acid sequences of HPV16 L1 and HPV6 L1 used for the development of a binary vaccine against cervical cancer and anogenital papillomatosis have been analyzed. For the analysis of antigenic determinants, the programs BepiPred-2.0: Sequential B-Cell Epitope Predictor, DiscoTope 2.0 Server and SYFPEITHI have been used. As a result of the analysis of probable B-cell linear determinants (epitopes), it has been found that in both types of HPV the proteins have approximately the same location and size of linear antigenic determinants; the difference is observed only in the form of small shifts in the size of several amino acid residues. However, there are some differences in the amino acid composition of epitopes; therefore, the possibility for cross-interaction of the antibodies with the antigens due to the similarity of linear antigenic determinants for B-cells is very small. The analysis of potential threedimensional epitopes for B-cells has shown that due to little difference between them the HPV16 L1 and HPV6 L1 proteins have no prerequisites for cross-interaction of the antibodies with the antigens belonging to the two different pathogenic HPV types. The analysis of probable linear epitopes for T-cells has revealed a common antigenic determinant in the two protein sequences. According to the rank made with the SYFPEITHI program, the amino acid sequence AQL(I)FNKPYWL is the second most likely antigenic determinant for T-cells. Meanwhile, the amino acid sequences of this determinant in HPV16 L1 and HPV6 L1 are virtually identical. There is a difference in only one position, but it is not critical due to the similarity of the physicochemical properties of amino acids, for which there is a replacement in the amino acid sequence of antigenic determinants. Consequently, some moderate cross-interaction of the antibodies to HPV16 L1 with the antigens of HPV6 L1 may be expected.

scholarly journals c-type Lysozymes: What do their introns hide?

2014 ◽  
Author(s):  
Pierre Jolles
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Biologically Active

The introns of five c-type lysozymes were translated into amino acid sequences: parts of them corresponded to fragments of biologically active proteins. The amino acid sequences of translated introns seem to have a similar behavior as those arising from exons.

The v-ski oncogene encodes a truncated set of c-ski coding exons with limited sequence and structural relatedness to v-myc

1989 ◽  
Vol 9 (9) ◽  
pp. 4038-4045
Author(s):  
E Stavnezer ◽  
D Brodeur ◽  
L A Brennan
Keyword(s):  
Amino Acid ◽  
Metal Binding ◽  
Avian Leukosis Virus ◽  
Amino Acid Sequences ◽  
Biologically Active ◽  
Predicted Amino Acid Sequence ◽  
Base Sequence ◽  
Reading Frame ◽  
Metal Binding Domain ◽  
Virus C

The nucleotide sequence of a biologically active v-ski gene from a cloned proviral segment shows that ski is a 1,312-base sequence embedded in the p19 region of the avian leukosis virus gag gene. The v-ski sequence contains a single open translational reading frame that encodes a polypeptide with a molecular mass of 49,000 daltons. The predicted amino acid sequence includes nuclear localization motifs that have been identified in other nuclear oncoproteins. It also contains a proline-rich region and a set of cysteine and histidine residues that could constitute a metal-binding domain. Two regions of the amino acid sequences of v-ski and v-myc are related, and the two proteins exhibit similar distributions of hydrophobic and hydrophilic amino acids. Cloned segments of the chicken c-ski proto-oncogene totaling 65 kilobases have been analyzed, and regions related to v-ski have been sequenced. The results indicate that v-ski is derived from at least five coding exons of c-ski, that it is correctly spliced, and that it is missing c-ski coding sequences at both its 5' and 3' ends. The c-ski and avian leukosis virus sequences that overlap the 5' virus/v-ski junction in Sloan-Kettering virus contain an 18-of-20-base sequence match that presumably played a role in the transduction of ski by facilitating virus/c-ski recombination.

Synthesis of biologically active analogs of luliberin with shortened amino acid sequences

1982 ◽  
Vol 18 (6) ◽  
pp. 732-737 ◽  
Author(s):  
S. V. Burov ◽  
S. V. Nikolaev ◽  
M. P. Smironova ◽  
G. E. Lupanova ◽  
Yu. F. Bobrov ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Biologically Active

Biofunctional properties of milk protein derived bioactive peptides -A review

2015 ◽  
Vol 34 (4) ◽  
Author(s):  
Prasad Patil ◽  
Akanksha Wadehra ◽  
Varsha Garg ◽  
Kanchan Munjal ◽  
Sudhir Kumar Tomar ◽  
...  
Keyword(s):  
Milk Protein ◽  
Bioactive Peptides ◽  
Therapeutic Potential ◽  
Proteolytic Enzymes ◽  
Biological Activities ◽  
Milk Proteins ◽  
Physiological Effect ◽  
Amino Acid Sequences ◽  
The Body ◽  
Biologically Active

Milk has long been acknowledged as a source of macro- and micro nutrients. Presently, several identified biologically active substances from milk and their derivatives has attracted much attention from the scientific community. These bioactive compounds confer many health benefits that might support disease prevention. Worldwide, there is an increasing interest in the therapeutic potential of bioactive peptides which collectively present a cornucopia of bioactivities for utilization in humans. Bioactive peptides are hydrolysates with specific amino acid sequences that exert a positive physiological effect on the body. Most of the biological activities are encrypted within the primary sequence of the native protein and can be released during digestion by proteolytic enzymes in the gastrointestinal tract or during fermentation and food processing. Milk protein is an important source of bioactive peptides which may contribute to regulate the nervous, gastrointestinal, and cardiovascular systems as well as the immune system. Milk protein derived bioactive peptides are shown to have antihypertensive, antimicrobial, immunomodulatory, antioxidative and mineral-binding properties. Bioactive peptides derived from milk proteins are of particular interest to the food industry due to the potential functional and physiological roles that they exhibit.

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