scholarly journals Possible role for a human adenovirus in the pathogenesis of celiac disease.

1984 ◽  
Vol 160 (5) ◽  
pp. 1544-1557 ◽  
Author(s):  
M F Kagnoff ◽  
R K Austin ◽  
J J Hubert ◽  
J E Bernardin ◽  
D D Kasarda
Keyword(s):  
Celiac Disease ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Monozygotic Twins ◽  
Human Adenovirus ◽  
Adenovirus Type ◽  
Data Bank ◽  
Antigenic Determinants ◽  
Amino Acid Residues ◽  
Primary Amino

Celiac disease in humans is activated by the dietary ingestion of wheat, rye, triticale, barley, and possibly oats. Gliadins in wheat and similar proteins in the other grains are known to activate disease in susceptible individuals. There is a striking association between celiac disease and HLA-B8, -DR3 and/or -DR7, and -DC3. Nonetheless, less than 0.2% of individuals with those serologic HLA specificities develop celiac disease and disease is not always concordant among monozygotic twins. We propose that additional environmental factors may be important in the pathogenesis of celiac disease. To investigate that possibility, we examined a data bank of protein sequences for other proteins that might share amino acid sequence homologies with A-gliadin, an alpha-gliadin component known to activate celiac disease and whose complete primary amino acid sequence is known. These studies demonstrate that A-gliadin shares a region of amino acid sequence homology with the 54-kD E1b protein of human adenovirus type 12 (Ad12), an adenovirus usually isolated from the intestinal tract. The region spans 12 amino acid residues, includes 8 residue identities and an identical pentapeptide, and is hydrophilic in both proteins. Antibody reactive with the 54-kD Ad12 E1b protein cross-reacts with A-gliadin, a 119 amino acid cyanogen bromide peptide of A-gliadin that spans the region of homology and a synthetic heptapeptide of A-gliadin from within the region of homology. We suggest that an encounter of the immune system with antigenic determinants produced during intestinal viral infection may be important in the pathogenesis of celiac disease.

Amino acid sequence of cyanogen bromide fragment CB5 of human hemopexin

1989 ◽  
Vol 54 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Ivan Kluh ◽  
Ladislav Morávek ◽  
Manfred Pavlík
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acid Hydrolysis ◽  
Cyanogen Bromide ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Mild Acid Hydrolysis ◽  
Methionine Residue ◽  
Cyanogen Bromide Fragment ◽  
Mild Acid

Cyanogen bromide fragment CB5 represents the region of the polypeptide chain of hemopexin between the fourth and fifth methionine residue (residues 232-352). It contains 120 amino acid residues in the following sequence: Arg-Cys-Ser-Pro-His-Leu-Val-Leu-Ser-Ala-Leu-Thr-Ser-Asp-Asn-His-Gly-Ala-Thr-Tyr-Ala-Phe-Ser-Gly-Thr-His-Tyr-Trp-Arg-Leu-Asp-Thr-Ser-Arg-Asp-Gly-Trp-His-Ser-Trp-Pro-Ile-Ala-His-Gln-Trp-Pro-Gln-Gly-Pro-Ser-Ala-Val-Asp-Ala-Ala-Phe-Ser-Trp-Glu-Glu-Lys-Leu-Tyr-Leu-Val-Gln-Gly-Thr-Gln-Val-Tyr-Val-Phe-Leu-Thr-Lys-Gly-Gly-Tyr-Thr-Leu-Val-Ser-Gly-Tyr-Pro-Lys-Arg-Leu-Glu-Lys-Glu-Val-Gly-Thr-Pro-His-Gly-Ile-Ile-Leu-Asp-Ser-Val-Asp-Ala-Ala-Phe-Ile-Cys-Pro-Gly-Ser-Ser-Arg-Leu-His-Ile-Met. The sequence was derived from the data on peptides prepared by cleavage of fragment CB5 by mild acid hydrolysis, by trypsin and chymotrypsin.

Chitosanase from Streptomyces sp. strain N174: a comparative review of its structure and function

1997 ◽  
Vol 75 (6) ◽  
pp. 687-696 ◽  
Author(s):  
Tamo Fukamizo ◽  
Ryszard Brzezinski
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Substrate Binding ◽  
Structure And Function ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Streptomyces Sp ◽  
Binding Cleft ◽  
And Function

Novel information on the structure and function of chitosanase, which hydrolyzes the beta -1,4-glycosidic linkage of chitosan, has accumulated in recent years. The cloning of the chitosanase gene from Streptomyces sp. strain N174 and the establishment of an efficient expression system using Streptomyces lividans TK24 have contributed to these advances. Amino acid sequence comparisons of the chitosanases that have been sequenced to date revealed a significant homology in the N-terminal module. From energy minimization based on the X-ray crystal structure of Streptomyces sp. strain N174 chitosanase, the substrate binding cleft of this enzyme was estimated to be composed of six monosaccharide binding subsites. The hydrolytic reaction takes place at the center of the binding cleft with an inverting mechanism. Site-directed mutagenesis of the carboxylic amino acid residues that are conserved revealed that Glu-22 and Asp-40 are the catalytic residues. The tryptophan residues in the chitosanase do not participate directly in the substrate binding but stabilize the protein structure by interacting with hydrophobic and carboxylic side chains of the other amino acid residues. Structural and functional similarities were found between chitosanase, barley chitinase, bacteriophage T4 lysozyme, and goose egg white lysozyme, even though these proteins share no sequence similarities. This information can be helpful for the design of new chitinolytic enzymes that can be applied to carbohydrate engineering, biological control of phytopathogens, and other fields including chitinous polysaccharide degradation. Key words: chitosanase, amino acid sequence, overexpression system, reaction mechanism, site-directed mutagenesis.

Vector expression of adenovirus type 5 E1a proteins: evidence for E1a autoregulation

1985 ◽  
Vol 5 (10) ◽  
pp. 2684-2696
Author(s):  
D H Smith ◽  
D M Kegler ◽  
E B Ziff
Keyword(s):  
Amino Acid ◽  
Simian Virus 40 ◽  
Adenovirus Type ◽  
Simian Virus ◽  
Mutant Form ◽  
Amino Acid Residues ◽  
Reading Frame ◽  
Acid Protein ◽  
Dna Replication Origin ◽  
E1a Protein

We transiently expressed adenovirus type C E1a proteins in wild-type or mutant form from plasmid vectors which have different combinations of E1a and simian virus 40 enhancer elements and which contain the DNA replication origin of SV40 and can replicate in COS 7 cells. We measured the levels of E1a mRNA encoded by the vectors and the transition regulation properties of the protein products. Three vectors encoded equivalent levels of E1a mRNA in COS 7 cells: (i) a plasmid encoding the wt 289-amino acid E1a protein (this complemented the E1a deletion mutant dl312 for early region E2a expression under both replicative and nonreplicative conditions); (ii) a vector for the wt 243-amino acid E1a protein (this complemented dl312 weakly and only under conditions of high multiplicities of dl312); (iii) a mutant, pSVXL105, in which amino acid residues-38 through 44 of the 289-amino acid E1a protein (which includes two highly conserved residues) are replaced by 3 novel amino acids (this also complemented dl312 efficiently). A fourth vector, mutant pSVXL3 with which linker substitution shifts the reading frame to encode a truncated 70-amino acid fragment from the amino terminus of the 289-amino acid protein, was unable to complement dl312. Surprisingly, pSVXL3 overexpressed E1a mRNA approximately 30-fold in COS 7 cells in comparison with the other vectors. The pSVXL3 overexpression could be reversed by cotransfection with a wt E1a vector. We suggest that wt E1a proteins regulate the levels of their own mRNAs through the recently described transcription repression functions of the 289- and 243-amino acid E1a protein products and that pSVXL3 fails to autoregulate negatively.

scholarly journals Intracellular Retention of the Corticotrophin-releasing Hormone (CRH) Precursor Within COS-7 Cells

1998 ◽  
Vol 46 (10) ◽  
pp. 1193-1197 ◽  
Author(s):  
Marcelo J. Perone ◽  
Simon Windeatt ◽  
Ewan Morrison ◽  
Andy Shering ◽  
Peter Tomasec ◽  
...  
Keyword(s):  
Amino Acid ◽  
Golgi Apparatus ◽  
Amino Acid Sequence ◽  
Protein Secretion ◽  
Intracellular Trafficking ◽  
Secretory Pathway ◽  
Intracellular Localization ◽  
Primary Amino Acid Sequence ◽  
Releasing Hormone ◽  
Primary Amino

We investigated the intracellular localization of CRH in transiently transfected COS-7 cells expressing the full-length rat corticotropin-releasing hormone (CRH) precursor cDNA. CRH synthesized by transfected COS-7 cells is mainly stored intracellularly. In contrast, CHO-K1 cells expressing the same CRH precursor stored and released equal amounts of immunoreactive (IR)-CRH. Ultrastructural analysis revealed that CRH is stored in electron-dense aggregates in the RER of transiently transfected COS-7 cells and does not migrate into the Golgi apparatus. On the basis of the different intracellular localization, storage, and release of CRH in COS-7 and CHO-K1 cells, we hypothesize that the intracellular trafficking of CRH within the constitutive secretory pathway for protein secretion not only depends on its primary amino acid sequence but might also be influenced by intracellular conditions or factors.

scholarly journals Diarrhea-Inducing Activity of Avian Rotavirus NSP4 Glycoproteins, Which Differ Greatly from Mammalian Rotavirus NSP4 Glycoproteins in Deduced Amino Acid Sequence, in Suckling Mice

2002 ◽  
Vol 76 (11) ◽  
pp. 5829-5834 ◽  
Author(s):  
Yoshio Mori ◽  
Mohammed Ali Borgan ◽  
Naoto Ito ◽  
Makoto Sugiyama ◽  
Nobuyuki Minamoto
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Suckling Mice

ABSTRACT Avian rotavirus NSP4 glycoproteins expressed in Escherichia coli acted as enterotoxins in suckling mice, as did mammalian rotavirus NSP4 glycoproteins, despite great differences in the amino acid sequences. The enterotoxin domain of PO-13 NSP4 exists in amino acid residues 109 to 135, a region similar to that reported in SA11 NSP4.

Plasmin-platelet interaction involves cleavage of functional thrombin receptor

1996 ◽  
Vol 271 (1) ◽  
pp. C54-C60 ◽  
Author(s):  
M. Kimura ◽  
T. T. Andersen ◽  
J. W. Fenton ◽  
W. F. Bahou ◽  
A. Aviv
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Platelet Activation ◽  
Synthetic Peptide ◽  
Time Dependent ◽  
Thrombin Receptor ◽  
Amino Acid Residues ◽  
Enzymatic Action ◽  
High Concentrations ◽  
Inhibition Of Thrombin

We tested the hypothesis that the inhibition of thrombin-induced platelet activation by plasmin is mediated via the enzymatic action of plasmin on the functional thrombin receptor. We monitored the binding of the anti-thrombin receptor antibody [anti-TR-(34-46)] to platelets; this binding is sensitive to the cleavage of the thrombin receptor at amino acid residues Arg-41 to Ser-42. Plasmin inhibited anti-TR-(34-46) binding in dose- and time-dependent manners. The inactive synthetic peptide with the amino acid sequence 40-55 of the thrombin receptor (D-FPRSFLLRNPNDKYEPF) was similarly cleaved by thrombin and plasmin to an active peptide (SFLLRNPNDKYEPF) that produced robust cytosolic Ca2+ responses. At high concentrations, plasmin itself can activate platelets. We explored this effect with the use of anti-TR-(1-160). This antibody abolished the cytosolic Ca2+ responses to thrombin and to the thrombin receptor-activating peptide SFLLRN but did not attenuate the plasmin-induced cytosolic Ca2+ response. Thus plasmin inhibits thrombin-evoked platelet activation by cleaving the thrombin receptor, but the plasmin-induced cytosolic Ca2+ response is not due to the generation of the tethered peptide of the thrombin receptor.

scholarly journals Hyaluronan-binding region of aggrecan from pig laryngeal cartilage. Amino acid sequence, analysis of N-linked oligosaccharides and location of the keratan sulphate

1992 ◽  
Vol 286 (3) ◽  
pp. 761-769 ◽  
Author(s):  
F P Barry ◽  
J U Gaw ◽  
C N Young ◽  
P J Neame
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Signal Peptidase ◽  
Amino Acid Residues ◽  
Terminal Sequence ◽  
Binding Region ◽  
Keratan Sulphate ◽  
Laryngeal Cartilage ◽  
Hyaluronan Binding

The hyaluronan-binding region (HABR) was prepared from pig laryngeal cartilage aggrecan and the amino acid sequence was determined. The HABR had two N-termini: one N-terminal sequence was Val-Glu-Val-Ser-Glu-Pro (367 amino acids in total), and a second N-terminal sequence (Ala-Ile-Ser-Val-Glu-Val; 370 amino acids in total) was found to arise due to alternate cleavage by the signal peptidase. The N-linked oligosaccharides were analysed by examining their reactivity with a series of lectins. It was found that the N-linked oligosaccharide on loop A was of the mannose type, while that on loop B was of the complex type. No reactivity was detected between the N-linked oligosaccharide on loop B' and any of the lectins. The location of keratan sulphate (KS) in the HABR was determined by Edman degradation of the immobilized KS-containing peptide. The released amino acid derivatives were collected and tested for the presence of epitope to antibody 5-D-4. On the basis of 5-D-4 reactivity and sequencing yields, the KS chains are attached to threonine residues 352 and 357. There is no KS at threonine-355. This site is not in fact in G1, but about 16 amino acid residues into the interglobular domain. Comparison of the structure of the KS chain from the HABR and from the KS domain of pig laryngeal cartilage aggrecan was made by separation on polyacrylamide gels of the oligosaccharides arising from digestion with keratanase. Comparison of the oligosaccharide maps suggests that the KS chains from both parts of the aggrecan molecule have the same structure.

scholarly journals Amino acid sequence and the cellular location of the Na+-dependent d-glucose symporters (SGLT1) in the ovine enterocyte and the parotid acinar cell

1995 ◽  
Vol 312 (1) ◽  
pp. 293-300 ◽  
Author(s):  
P S Tarpey ◽  
I S Wood ◽  
S P Shirazi-Beechey ◽  
R B Beechey
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Amino Acid Sequences ◽  
Primary Amino Acid Sequence ◽  
Parotid Acinar Cells ◽  
Parotid Acinar Cell ◽  
Primary Amino

The Na(+)-dependent D-glucose symporter has been shown to be located on the basolateral domain of the plasma membrane of ovine parotid acinar cells. This is in contrast to the apical location of this transporter in the ovine enterocyte. The amino acid sequences of these two proteins have been determined. They are identical. The results indicated that the signals responsible for the differential targeting of these two proteins to the apical and the basal domains of the plasma membrane are not contained within the primary amino acid sequence.

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