scholarly journals Amino Acids 785, 787 of the Na+/H+ Exchanger Cytoplasmic Tail Modulate Protein Activity and Tail Conformation

2021 ◽  
Vol 22 (21) ◽  
pp. 11349
Author(s):  
Xiuju Li ◽  
Tommy Tu ◽  
Sicheng Quan ◽  
Francisco J. Quintero ◽  
Richard Fahlman ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Apparent Molecular Weight ◽  
Slight Reduction ◽  
Membrane Domain ◽  
Protein Activity ◽  
Extracellular Sodium ◽  
Vitro Protein

The mammalian Na+/H+ exchanger isoform 1 (NHE1) is a plasma membrane protein ubiquitously present in humans. It regulates intracellular pH by removing an intracellular proton in exchange for an extracellular sodium. It consists of a 500 amino acid membrane domain plus a 315 amino acid, regulatory cytosolic tail. Here, we investigated the effect of mutation of two amino acids of the regulatory tail, Ser785 and Ser787, that were similar in location and context to two amino acids of the Arabidopsis Na+/H+ exchanger SOS1. Mutation of these two amino acids to either Ala or phosphomimetic Glu did not affect surface targeting but led to a slight reduction in the level of protein expressed. The activity of the NHE1 protein was reduced in the phosphomimetic mutations and the effect was due to a decrease in Vmax activity. The Ser to Glu mutations also caused a change in the apparent molecular weight of both the full-length protein and of the cytosolic tail of NHE1. A conformational change in this region was indicated by differential trypsin sensitivity. We also found that a peptide containing amino acids 783–790 bound to several more proximal regions of the NHE1 tail in in vitro protein interaction experiments. The results are the first characterization of these two amino acids and show that they have significant effects on enzyme kinetics and the structure of the NHE1 protein.

scholarly journals Effect of Blanching Treatments against Protein Content and Amino Acid Drumstick Leaves (Moringa oleifera)

2013 ◽  
Vol 2 (1) ◽  
pp. 101 ◽  
Author(s):  
Titi Mutiara Kirana ◽  
Harijono Harijono ◽  
Teti Estiasih ◽  
Endang Sriwahyuni
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Bicarbonate ◽  
Moringa Oleifera ◽  
Amino Acid Content ◽  
Protein Digestibility ◽  
Lysine Content ◽  
In Vitro Protein Digestibility ◽  
Vitro Protein

Three blanching methods, namely boiling, steaming, and boiling+sodium bicarbonate, were used to evaluate amino acids contens and score of Moringa leaves under different blanching. Results showed that blanching had a great effect on amino acids and scores of Moringa leaves and their digestibility increased. Different methods of blanching had variable effects on Moringa leaves’ amino acids and digestibility<ins datetime="2012-12-12T14:13" cite="mailto:printer"> </ins>significantly (p&lt;=0.05). Steam blanching Moringa leaves had the highest amino acid content by 31.49%. Results also revealed that under different blanching Moringa leaves at levels of leucine of steam and boil+sodium bicarbonate samples, lysine content of boil and steam blanching are higher than those of<ins datetime="2012-12-12T14:17" cite="mailto:printer"> </ins>FAO/WHO requirement pattern. The in vitro protein digestibility under study ranged from 49.6 to 52.3%.

scholarly journals Amino Acids 563–566 of the Na+/H+ Exchanger Isoform 1 C-Terminal Cytosolic Tail Prevent Protein Degradation and Stabilize Protein Expression and Activity

2020 ◽  
Vol 21 (5) ◽  
pp. 1737 ◽  
Author(s):  
Xiuju Li ◽  
Debajyoti Dutta ◽  
Martin Jung ◽  
Richard Zimmermann ◽  
Larry Fliegel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Expression ◽  
Protein Degradation ◽  
Stop Codon ◽  
Protein A ◽  
Membrane Domain ◽  
Protein Levels ◽  
Extracellular Sodium ◽  
Reduced Activity

Isoform one of the mammalian Na+/H+ exchanger is a plasma membrane protein that is ubiquitously present in humans. It regulates intracellular pH through the removal of one intracellular proton in exchange for a single extracellular sodium. It consists of a 500 amino acid membrane domain plus a 315 amino acid, C-terminal tail. We examined amino acids of the C-terminal tail that are important in the targeting and activity of the protein. A previous study demonstrated that stop codon polymorphisms can result in decreased activity, expression, targeting and enhanced protein degradation. Here, we determine elements that are critical in these anomalies. A series of progressive deletions of the C-terminal tail demonstrated a progressive decrease in activity and targeting, though these remained until a final drop off with the deletion of amino acids 563–566. The deletion of the 562LIAGERS568 sequence or the alteration to the 562LAAAARS568 sequence caused the decreased protein expression, aberrant targeting, reduced activity and enhanced degradation of the Na+/H+ exchanger (NHE1) protein. The 562LIAGERS568 sequence bound to other regions of the C-terminal cytosolic domain. We suggest this region is necessary for the activity, targeting, stability, and expression of the NHE1 protein. The results define a new sequence that is important in maintenance of NHE1 protein levels and activity.

scholarly journals Purification of a high-molecular-weight somatoliberin (growth-hormone-releasing factor) from pig hypothalami

1983 ◽  
Vol 209 (3) ◽  
pp. 643-651 ◽  
Author(s):  
J E C Sykes ◽  
P J Lowry
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Amino Acid ◽  
Response Curve ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Amino Acid Residues ◽  
Growth Hormone Releasing Factor

Preliminary observations [Sykes & Lowry (1980) J. Endocrinol. 85, 42P-43P] had suggested that the major hypothalamic somatoliberin (growth-hormone-releasing factor) was a larger peptide than the other characterized hypothalamic factors, with an elution position on Sephadex G-50 between those of neurophysin and corticotropin. The present paper reports the isolation and preliminary characterization of pig hypothalamic somatoliberin. Acid extracts of pig stalk median eminence were purified by gel filtration and preparative and analytical high-pressure liquid chromatography to yield a preparation that was specific in the release of somatotropin (growth hormone) in vitro, giving a steep dose-response curve at doses in the range 0.20-3.0 ng. Amino acid analysis revealed a non-cysteine-containing peptide with a high number of glutamate (or glutamine) and aspartate (or asparagine) residues. The peptide had about 56-57 amino acid residues and an apparent molecular weight of 6400, in keeping with its elution position on a column of Sephadex G-50.

scholarly journals Novel OXA-10-Derived Extended-Spectrum β-Lactamases Selected In Vivo or In Vitro

1998 ◽  
Vol 42 (12) ◽  
pp. 3113-3116 ◽  
Author(s):  
P. Mugnier ◽  
I. Casin ◽  
A. T. Bouthors ◽  
E. Collatz
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Clavulanic Acid ◽  
Extended Spectrum ◽  
Gene Coding ◽  
Lactamase Gene

ABSTRACT A clinical isolate of Pseudomonas aeruginosa, PAe191, was found to be highly resistant to all anti-Pseudomonasβ-lactam antibiotics (except imipenem) and resistant also to aminoglycosides. It produced a β-lactamase (with an apparent pI of 7.6) which was not inhibited by clavulanic acid. Cloning and characterization of the β-lactamase gene showed that it coded for a novel extended-spectrum OXA-10 variant, called OXA-19, which differed from OXA-10 by nine amino acids and from OXA-13 by two, i.e., Asn in position 73 (Asn73) instead of Ser and Asp157 instead of Gly. Asparagine in position 157 is implicated in resistance to ceftazidime, while the amino acid in position 73, in this variant, seems to condition the level of resistance to penicillins. The oxa19gene was found to be inserted, in a typical integron structure, immediately downstream from anaac(6′)-Ib gene coding for an aminoglycoside acetyltransferase variant, which was called AAC(6′)-Ib9.

Characterization of murine A-raf, a new oncogene related to the v-raf oncogene

1986 ◽  
Vol 6 (7) ◽  
pp. 2655-2662
Author(s):  
M Huleihel ◽  
M Goldsborough ◽  
J Cleveland ◽  
M Gunnell ◽  
T Bonner ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Gene Function ◽  
Fusion Gene ◽  
Ras Gene ◽  
Newborn Mice ◽  
Murine Spleen

A 1.6-kilobase cDNA (A-raf) has been isolated from a murine spleen cDNA library which encodes part of a protein related to the raf oncogene. Its amino acid sequence has 85% homology to raf in a central portion of 100 amino acids. In contrast to raf, A-raf shows a highly restricted tissue distribution of expression, with highest levels observed in epididymis, followed by intestine. When incorporated into a retrovirus, the resulting gag-A-raf fusion gene causes transformation in vitro and induces tumors in newborn mice. Thus, A-raf represents a new proto-oncogene. Transformation by A-raf is independent of ras gene function, as is the case for raf and mos but not other oncogenes.

scholarly journals Characterization of murine A-raf, a new oncogene related to the v-raf oncogene.

1986 ◽  
Vol 6 (7) ◽  
pp. 2655-2662 ◽  
Author(s):  
M Huleihel ◽  
M Goldsborough ◽  
J Cleveland ◽  
M Gunnell ◽  
T Bonner ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Gene Function ◽  
Fusion Gene ◽  
Ras Gene ◽  
Newborn Mice ◽  
Murine Spleen

A 1.6-kilobase cDNA (A-raf) has been isolated from a murine spleen cDNA library which encodes part of a protein related to the raf oncogene. Its amino acid sequence has 85% homology to raf in a central portion of 100 amino acids. In contrast to raf, A-raf shows a highly restricted tissue distribution of expression, with highest levels observed in epididymis, followed by intestine. When incorporated into a retrovirus, the resulting gag-A-raf fusion gene causes transformation in vitro and induces tumors in newborn mice. Thus, A-raf represents a new proto-oncogene. Transformation by A-raf is independent of ras gene function, as is the case for raf and mos but not other oncogenes.

scholarly journals Avoided motifs: short amino acid strings missing from protein datasets

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Function ◽  
Large Protein ◽  
New Approach ◽  
Cellular Context ◽  
Human Proteins ◽  
Context Specific ◽  
Protein Datasets

Abstract According to the amino acid composition of natural proteins, it could be expected that all possible sequences of three or four amino acids will occur at least once in large protein datasets purely by chance. However, in some species or cellular context, specific short amino acid motifs are missing due to unknown reasons. We describe these as Avoided Motifs, short amino acid combinations missing from biological sequences. Here we identify 209 human and 154 bacterial Avoided Motifs of length four amino acids, and discuss their possible functionality according to their presence in other species. Furthermore, we determine two Avoided Motifs of length three amino acids in human proteins specifically located in the cytoplasm, and two more in secreted proteins. Our results support the hypothesis that the characterization of Avoided Motifs in particular contexts can provide us with information about functional motifs, pointing to a new approach in the use of molecular sequences for the discovery of protein function.

scholarly journals FRUCTOSE-AMINO ACIDS IN LIVER: STIMULI OF AMINO ACID INCORPORATION IN VITRO

1955 ◽  
Vol 215 (1) ◽  
pp. 111-124 ◽  
Author(s):  
Henry Borsook ◽  
Adolph Abrams ◽  
Peter H. Lowy
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

scholarly journals Transdermal Delivery Systems for Ibuprofen and Ibuprofen Modified with Amino Acids Alkyl Esters Based on Bacterial Cellulose

2021 ◽  
Vol 22 (12) ◽  
pp. 6252
Author(s):  
Paula Ossowicz-Rupniewska ◽  
Rafał Rakoczy ◽  
Anna Nowak ◽  
Maciej Konopacki ◽  
Joanna Klebeko ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Cellulose ◽  
Acid Ester ◽  
Active Pharmaceutical Ingredient ◽  
Amino Acid Ester ◽  
Isopropyl Ester ◽  
Isopropyl Esters ◽  
Transdermal Application

The potential of bacterial cellulose as a carrier for the transport of ibuprofen (a typical example of non-steroidal anti-inflammatory drugs) through the skin was investigated. Ibuprofen and its amino acid ester salts-loaded BC membranes were prepared through a simple methodology and characterized in terms of structure and morphology. Two salts of amino acid isopropyl esters were used in the research, namely L-valine isopropyl ester ibuprofenate ([ValOiPr][IBU]) and L-leucine isopropyl ester ibuprofenate ([LeuOiPr][IBU]). [LeuOiPr][IBU] is a new compound; therefore, it has been fully characterized and its identity confirmed. For all membranes obtained the surface morphology, tensile mechanical properties, active compound dissolution assays, and permeation and skin accumulation studies of API (active pharmaceutical ingredient) were determined. The obtained membranes were very homogeneous. In vitro diffusion studies with Franz cells were conducted using pig epidermal membranes, and showed that the incorporation of ibuprofen in BC membranes provided lower permeation rates to those obtained with amino acids ester salts of ibuprofen. This release profile together with the ease of application and the simple preparation and assembly of the drug-loaded membranes indicates the enormous potentialities of using BC membranes for transdermal application of ibuprofen in the form of amino acid ester salts.

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