scholarly journals The CFTR-derived peptides as a model of sequence-specific protein aggregation

2007 ◽  
Vol 12 (3) ◽  
Author(s):  
Daniel Bąk ◽  
Garry Cutting ◽  
Michał Milewski
Keyword(s):  
Amino Acid ◽  
Protein Aggregation ◽  
Mammalian Cells ◽  
Specific Protein ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Aggregation Pattern ◽  
C Terminus ◽  
Crucial Component ◽  
Modified Peptides

AbstractProtein aggregation is a hallmark of a growing group of pathologies known as conformational diseases. Although many native or mutated proteins are able to form aggregates, the exact amino acid sequences involved in the process of aggregation are known only in a few cases. Hence, there is a need for different model systems to expand our knowledge in this area. The so-called ag region was previously found to cause the aggregation of the C-terminal fragment of the cystic fibrosis transmembrane conductance regulator (CFTR). To investigate whether this specific amino acid sequence is able to induce protein aggregation irrespective of the amino acid context, we altered its position within the CFTR-derived C-terminal peptide and analyzed the localization of such modified peptides in transfected mammalian cells. Insertion of the ag region into a different amino acid background affected not only the overall level of intracellular protein aggregation, but also the morphology and subcellular localization of aggregates, suggesting that sequences other than the ag region can substantially influence the peptide’s behavior. Also, the introduction of a short dipeptide (His-Arg) motif, a crucial component of the ag region, into different locations within the C-terminus of CFTR lead to changes in the aggregation pattern that were less striking, although still statistically significant. Thus, our results indicate that even subtle alterations within the aggregating peptide can affect many different aspects of the aggregation process.

scholarly journals Formation of Pyrazines in Maillard Model Systems: Effects of Structures of Lysine-Containing Dipeptides/Tripeptides

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 273
Author(s):  
Furong Wang ◽  
Hailiang Shen ◽  
Ting Liu ◽  
Xi Yang ◽  
Yali Yang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sunflower Seed ◽  
Seed Oil ◽  
Reaction System ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Sunflower Seed Oil ◽  
C Terminus ◽  
And Control

At present, most investigations involving the Maillard reaction models have focused on free amino acids (FAAs), whereas the effects of peptides on volatile products are poorly understood. In our study, the formation mechanism of pyrazines, which were detected as characteristic volatiles in sunflower seed oil, from the reaction system of glucose and lysine-containing dipeptides and tripeptides was studied. The effect of the amino acid sequences of the dipeptides and tripeptides on pyrazine formation was further highlighted. Four different dipeptides and six tripeptides were selected. The results showed that the production of pyrazines in the lysine-containing dipeptide models was higher than that in the tripeptide and control models. Compounds 2,5(6)-Dimethylpyrazine and 2,3,5-trimethylpyrazine were the main pyrazine compounds in the dipeptide models. Furthermore, the C- or N-terminal amino acids of lysine-containing dipeptides can exert an important effect on the formation of pyrazines. In dipeptide models with lysine at the C-terminus, the content of total pyrazines followed the order of Arg−Lys > His−Lys; the order of the total pyrazine content was Lys−His > Lys−Arg in dipeptide models with N-terminal lysine. Additionally, for the tripeptide models with different amino acid sequences, more pyrazines and a greater variety of pyrazines were detected in the tripeptide models with N-terminal lysine/arginine than in the tripeptide models with N-terminal histidine. However, the total pyrazine content and the percentage of pyrazines in the total volatiles were similar in the tripeptide models with the same amino acids at the N-terminus. This study clearly illustrates the ability of dipeptides and tripeptides containing lysine, arginine and histidine to form pyrazines, improving volatile formation during sunflower seed oil processing.

Molecular cloning and biochemical characterization of a new mouse testis soluble-zinc-metallopeptidase of the neprilysin family

2000 ◽  
Vol 347 (2) ◽  
pp. 419-429 ◽  
Author(s):  
Galia GHADDAR ◽  
Andréa Frota RUCHON ◽  
Mélanie CARPENTIER ◽  
Mieczyslaw MARCINKIEWICZ ◽  
Nabil G. SEIDAH ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mammalian Cells ◽  
Biochemical Characterization ◽  
Transmembrane Domain ◽  
Amino Acid Sequences ◽  
Mouse Testis ◽  
Peptidase Activity ◽  
Converting Enzyme ◽  
C Terminus ◽  
The Family

Because of their roles in controlling the activity of several bio-active peptides, members of the neprilysin family of zinc metallopeptidases have been identified as putative targets for the design of therapeutic agents. Presently, six members have been reported, these are: neprilysin, endothelin-converting enzyme (ECE)-1 and ECE-2, the Kell blood group protein, PHEX (product of the phosphate-regulating gene with homologies to endopeptidase on the X chromosome) and X-converting enzyme (XCE). In order to identify new members of this important family of peptidases, we designed a reverse transcriptase-PCR strategy based on conserved amino acid sequences of neprilysin, ECE-1 and PHEX. We now report the cloning from mouse testis of a novel neprilysin-like peptidase that we called NL1. NL1 is a glycoprotein that, among the members of the family, shows the strongest sequence identity with neprilysin. However, in contrast with neprilysin and other members of the family which are type II integral membrane proteins, NL1 was secreted when expressed in cultured mammalian cells, likely due to cleavage by a subtilisin-like convertase at a furin-like site located 22 amino acid residues in the C-terminus of the transmembrane domain. The recombinant enzyme exhibited neprilysin-like peptidase activity and was efficiently inhibited by phosphoramidon and thiorphan, two inhibitors of neprilysin. Northern blot analysis and in situ hybridization showed that NL1 mRNA was found predominantly in testis, specifically in round and elongated spermatids. This distribution of NL1 mRNA suggests that it could be involved in sperm formation or other processes related to fertility.

scholarly journals The Extracellular Transport Signal of the Vibrio cholerae Endochitinase (ChiA) Is a Structural Motif Located between Amino Acids 75 and 555

2002 ◽  
Vol 184 (8) ◽  
pp. 2225-2234 ◽  
Author(s):  
Jason P. Folster ◽  
Terry D. Connell
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Vibrio Cholerae ◽  
Structural Information ◽  
Amino Acid Sequences ◽  
Structural Motif ◽  
Terminal Branch ◽  
C Terminus ◽  
N Terminus ◽  
Extracellular Transport

ABSTRACT ChiA, an 88-kDa endochitinase encoded by the chiA gene of the gram-negative enteropathogen Vibrio cholerae, is secreted via the eps-encoded main terminal branch of the general secretory pathway (GSP), a mechanism which also transports cholera toxin. To localize the extracellular transport signal of ChiA that initiates transport of the protein through the GSP, a chimera comprised of ChiA fused at the N terminus with the maltose-binding protein (MalE) of Escherichia coli and fused at the C terminus with a 13-amino-acid epitope tag (E-tag) was expressed in strain 569B(chiA::Kanr), a chiA-deficient but secretion-competent mutant of V. cholerae. Fractionation studies revealed that blockage of the natural N terminus and C terminus of ChiA did not prevent secretion of the MalE-ChiA-E-tag chimera. To locate the amino acid sequences which encoded the transport signal, a series of truncations of ChiA were engineered. Secretion of the mutant polypeptides was curtailed only when ChiA was deleted from the N terminus beyond amino acid position 75 or from the C terminus beyond amino acid 555. A mutant ChiA comprised of only those amino acids was secreted by wild-type V. cholerae but not by an epsD mutant, establishing that amino acids 75 to 555 independently harbored sufficient structural information to promote secretion by the GSP of V. cholerae. Cys77 and Cys537, two cysteines located just within the termini of ChiA(75-555), were not required for secretion, indicating that those residues were not essential for maintaining the functional activity of the ChiA extracellular transport signal.

Expression of a gene family in the dimorphic fungus Mucor racemosus which exhibits striking similarity to human ras genes

1990 ◽  
Vol 10 (12) ◽  
pp. 6654-6663
Author(s):  
W L Casale ◽  
D G Mcconnell ◽  
S Y Wang ◽  
Y J Lee ◽  
J E Linz
Keyword(s):  
Amino Acid ◽  
Cell Development ◽  
Amino Acid Sequences ◽  
Model Systems ◽  
Striking Similarity ◽  
Ras Proteins ◽  
Mucor Racemosus ◽  
Dimorphic Fungus ◽  
Transcript Accumulation ◽  
Ras Genes

Sporulation, spore germination, and yeast-hypha dimorphism in the filamentous fungus Mucor racemosus provide useful model systems to study cell development in eucaryotic cells. Three RAS genes (MRAS1, MRAS2, and MRAS3) from M. racemosus have been cloned, and their nucleotide sequences have been determined. The predicted amino acid sequences and the sizes of the three MRAS proteins exhibit a high degree of similarity with other ras proteins, including that encoded by H-ras, which have been implicated in regulation of proliferation and development in eucaryotic cells by mediating signal transduction pathways. The MRAS proteins show conservation of functional domains proposed for ras proteins, including guanine nucleotide interaction domains, an effector domain, a binding epitope for neutralizing antibody Y13-259, and the COOH-terminal CAAX box, which is a site of thiocylation and membrane attachment. Amino acid sequences unique to each MRAS protein occur adjacent to the CAAX box, consistent with the location of the hypervariable region in other ras proteins. Northern (RNA) analysis was used to study expression of the three MRAS genes in relation to cell development. Gene-specific probes for two of these genes, MRAS1 and MRAS3, hybridized to different 1.3-kb mRNA transcripts. The accumulation of these transcripts depended on the developmental stage, and this pattern was different between the two MRAS genes. No transcript for MRAS2 was detected in the developmental stages examined. The unique patterns of MRAS transcript accumulation suggest that individual MRAS genes and proteins may play distinct roles in cell growth or development.

scholarly journals Amino acid sequences around the cystine residues in horse growth hormone

1968 ◽  
Vol 109 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Louise Oliver ◽  
Anne Stockell Hartree
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Amino Acid ◽  
Growth Hormones ◽  
Amino Acid Sequences ◽  
The Other ◽  
Published Data ◽  
C Terminus

The cystine-containing peptides of horse growth hormone were isolated and their amino acid sequences determined. Four unique half-cystine residues occur in two peptides, one containing 11 and the other, at the C-terminus of the protein, 15 amino acids. These sequences are compared with published data on growth hormones from other species.

Targeting motifs and functional parameters governing the assembly of connexins into gap junctions

2000 ◽  
Vol 349 (1) ◽  
pp. 281-287 ◽  
Author(s):  
Patricia E. M. MARTIN ◽  
James STEGGLES ◽  
Claire WILSON ◽  
Shoeb AHMAD ◽  
W. Howard EVANS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gap Junctions ◽  
Gap Junction ◽  
Mammalian Cells ◽  
Fluorescent Protein ◽  
Lucifer Yellow ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Green Fluorescent

To study the assembly of gap junctions, connexin-green-fluorescent-protein (Cx-GFP) chimeras were expressed in COS-7 and HeLa cells. Cx26- and Cx32-GFP were targeted to gap junctions where they formed functional channels that transferred Lucifer Yellow. A series of Cx32-GFP chimeras, truncated from the C-terminal cytoplasmic tail, were studied to identify amino acid sequences governing targeting from intracellular assembly sites to the gap junction. Extensive truncation of Cx32 resulted in failure to integrate into membranes. Truncation of Cx32 to residue 207, corresponding to removal of most of the 78 amino acids on the cytoplasmic C-terminal tail, led to arrest in the endoplasmic reticulum and incomplete oligomerization. However, truncation to amino acid 219 did not impair Cx oligomerization and connexon hemichannels were targeted to the plasma membrane. It was concluded that a crucial gap-junction targeting sequence resides between amino acid residues 207 and 219 on the cytoplasmic C-terminal tail of Cx32. Studies of a Cx32E208K mutation identified this as one of the key amino acids dictating targeting to the gap junction, although oligomerization of this site-specific mutation into hexameric hemichannels was relatively unimpaired. The studies show that expression of these Cx-GFP constructs in mammalian cells allowed an analysis of amino acid residues involved in gap-junction assembly.

scholarly journals Occurrence of PG-Lb, a leucine-rich small chondroitin/dermatan sulphate proteoglycan in mammalian epiphyseal cartilage: molecular cloning and sequence analysis of the mouse cDNA

1996 ◽  
Vol 318 (3) ◽  
pp. 909-914 ◽  
Author(s):  
Kazuhiro KURITA ◽  
Tamayuki SHINOMURA ◽  
Minoru UJITA ◽  
Masahiro ZAKO ◽  
Daihei KIDA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Epiphyseal Cartilage ◽  
Newborn Mouse ◽  
Dermatan Sulphate ◽  
Cdna Fragment ◽  
Sulphate Proteoglycan ◽  
C Terminus ◽  
Degenerate Oligonucleotide

PG-Lb is a chondroitin/dermatan sulphate proteoglycan first isolated from chick embryo limb cartilage. It had been assumed that osteoglycin represents its mammalian homologue. However, partial amino acid sequences of a novel proteoglycan from bovine epiphyseal cartilage showed high identity with those of chick PG-Lb (P. Neame, L. Rosenberg and M. Höök, personal communication). Reverse transcriptase PCR using degenerate oligonucleotide primers gave a cDNA fragment that might correspond to mouse PG-Lb. We isolated a clone from a cDNA library of newborn mouse epiphyseal cartilage using the cDNA fragment as a probe. The cloned cDNA was 1430 bp long and contained a 966 bp open reading frame which encoded the core protein consisting of 322 amino acid residues. The deduced amino acid sequence showed a high overall identity with chick PG-Lb (about 62%, reaching about 80% over the carboxyl two-thirds). In addition, the amino acid sequence contained a signal peptide, six cysteine residues at the invariant relative position to chick PG-Lb, six leucine-rich repeats at the carboxyl two-thirds, three possible glycosaminoglycan-attachment sites (two sites at the N-terminal side and one site at the C-terminus) and two possible Asn-glycosylation sites near the C-terminus. Northern-blot analysis demonstrated the specific expression of a 1.5 kb message in cartilage and testis. These structural features and the characteristic expression suggest that the cloned molecule is mouse PG-Lb.

Characterization, chromosomal mapping, and expression of different ubiquitin fusion protein genes in tissues from control and heat-shocked maize seedlings

1996 ◽  
Vol 74 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Ling Liu ◽  
J. Roger H. Frappier ◽  
Karen d'Ailly ◽  
Burr G. Atkinson ◽  
Daniel S. Maillet ◽  
...  
Keyword(s):  
Amino Acid ◽  
Heat Shock ◽  
Fusion Protein ◽  
Specific Protein ◽  
Amino Acid Sequences ◽  
Chromosomal Mapping ◽  
Repeat Units ◽  
Acid Protein ◽  
Specific Mrnas ◽  
Shock Proteins

Organisms possess at least two multigene families of ubiquitins: the polyubiquitins, with few to several repeat units, which encode a ubiquitin monomer, and the ubiquitin fusion (or extension) protein genes, which encode a single ubiquitin monomer and a specific protein. This report provides details about two ubiquitin fusion protein genes in maize referred to as MubG7 (uwo 1) and MubG10 (uwo 2). Each has one nearly identical ubiquitin coding unit fused without an intervening nucleotide to an unrelated, 237-nucleotide sequence that encodes for a 79 amino acid protein. The derived amino acid sequences of the two fusion proteins show that they differ by five amino acids (substitution by either a serine or threonine). MubG7 maps to chromosome 8L162 and MubG10 maps to chromosome 1L131. Analyses of the role(s) of these genes in response to heat shock (1 h at 42.5 °C) reveal that the level of these fusion protein mRNAs in the radicles or plumules from 2-day-old seedlings does not change; however, heat shock does cause a marked reduction in the accumulation of these same gene-specific mRNAs in the radicles and plumules of 5-day-old seedlings. These data confirm the suggestion from our earlier work that there is precise modulation, in a gene-specific manner, of the response to developmental as well as environmental signals.Key words: ubiquitin, ubiquitin extension (or fusion) protein, maize, heat shock, heat shock proteins, gene expression, chromosome map.

scholarly journals 2P065 Thermodynamic analysis of protein aggregation using highly simplified amino acid sequences

2005 ◽  
Vol 45 (supplement) ◽  
pp. S136
Author(s):  
Yutaka Kuroda ◽  
Atsushi Kato ◽  
Kunitsugu Soda
Keyword(s):  
Amino Acid ◽  
Protein Aggregation ◽  
Thermodynamic Analysis ◽  
Amino Acid Sequences

scholarly journals Differential Localization and Function of PB1-F2 Derived from Different Strains of Influenza A Virus

2010 ◽  
Vol 84 (19) ◽  
pp. 10051-10062 ◽  
Author(s):  
Chi-Jene Chen ◽  
Guang-Wu Chen ◽  
Ching-Ho Wang ◽  
Chih-Heng Huang ◽  
Yeau-Ching Wang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A Virus ◽  
Influenza A ◽  
Amino Acid Sequences ◽  
Wild Type ◽  
Mitochondrial Localization ◽  
Sequence Context ◽  
C Terminus ◽  
Different Strains ◽  
And Function

ABSTRACT PB1-F2 is a viral protein that is encoded by the PB1 gene of influenza A virus by alternative translation. It varies in length and sequence context among different strains. The present study examines the functions of PB1-F2 proteins derived from various human and avian viruses. While H1N1 PB1-F2 was found to target mitochondria and enhance apoptosis, H5N1 PB1-F2, surprisingly, did not localize specifically to mitochondria and displayed no ability to enhance apoptosis. Introducing Leu into positions 69 (Q69L) and 75 (H75L) in the C terminus of H5N1 PB1-F2 drove 40.7% of the protein to localize to mitochondria compared with the level of mitochondrial localization of wild-type H5N1 PB1-F2, suggesting that a Leu-rich sequence in the C terminus is important for targeting of mitochondria. However, H5N1 PB1-F2 contributes to viral RNP activity, which is responsible for viral RNA replication. Lastly, although the swine-origin influenza virus (S-OIV) contained a truncated form of PB1-F2 (12 amino acids [aa]), potential mutation in the future may enable it to contain a full-length product. Therefore, the functions of this putative S-OIV PB1-F2 (87 aa) were also investigated. Although this PB1-F2 from the mutated S-OIV shares only 54% amino acid sequence identity with that of seasonal H1N1 virus, it also increased viral RNP activity. The plaque size and growth curve of the viruses with and without S-OIV PB1-F2 differed greatly. The PB1-F2 protein has various lengths, amino acid sequences, cellular localizations, and functions in different strains, which result in strain-specific pathogenicity. Such genetic and functional diversities make it flexible and adaptable in maintaining the optimal replication efficiency and virulence for various strains of influenza A virus.

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