scholarly journals The human erythrocyte anion-transport protein. Further amino acid sequence from the integral membrane domain homologous with the murine protein

1986 ◽  
Vol 235 (3) ◽  
pp. 899-901 ◽  
Author(s):  
C J Brock ◽  
M J A Tanner
Keyword(s):  
Amino Acid ◽  
Human Erythrocyte ◽  
Proteolytic Enzymes ◽  
Transmembrane Helix ◽  
Anion Transport ◽  
Transport Protein ◽  
Membrane Domain ◽  
C Terminus ◽  
N Terminus ◽  
Almost All

Sequences from the human erythrocyte anion-transport protein homologous with residues 417-449 and 794-813 of the murine erythrocyte anion-transport protein have been determined. The former sequence includes the putative transmembrane helix closest to the N-terminus of the protein. The latter sequence traverses almost all of the lipid bilayer and is located towards the C-terminus of the protein. Sites have been identified by alignment with the murine sequence in the integral membrane domain that are accessible to proteolytic enzymes. Sequences from the integral membrane domain of the erythrocyte anion-transport protein are highly conserved.

scholarly journals Monoclonal antibodies to the membrane domain of the human erythrocyte anion transport protein. Localization of the C-terminus of the protein to the cytoplasmic side of the red cell membrane and distribution of the protein in some human tissues

1989 ◽  
Vol 258 (1) ◽  
pp. 211-220 ◽  
Author(s):  
S D Wainwright ◽  
M J A Tanner ◽  
G E M Martin ◽  
J E Yendle ◽  
C Holmes
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Membrane ◽  
Human Erythrocyte ◽  
Anion Transport ◽  
Transport Protein ◽  
Red Cell ◽  
Membrane Domain ◽  
Red Cell Membrane ◽  
C Terminus ◽  
Cytoplasmic Side

(1) We have prepared murine monoclonal antibodies to the membrane domain of the human erythrocyte anion transport protein (band 3). (2) All of these antibodies react with regions of the protein located at the cytoplasmic surface of the red cell. (3) One of the antibodies reacts with an epitope present on a cytoplasmic loop of the protein located between the C-terminus and a point 168 amino acids from the C-terminus. The other antibodies recognize different epitopes on the C-terminal tail of the protein and the sequences likely to be involved in these epitopes are defined. (4) Our results show that the C-terminus of the red-cell anion transport protein is located on the cytoplasmic side of the red-cell membrane. (5) None of the antibodies inhibited sulphate exchange transport when introduced into resealed red-cell membranes; however, the bivalent form of one of the antibodies reduced the inhibitory potency of 4-acetamido-4'-isothiocyanatostilbene disulphonate on sulphate exchange transport in resealed erythrocyte membranes. (6) Immunostaining of human kidney sections with the antibodies showed strong staining of the basolateral membrane of some but not all of the epithelial cells of distal tubules and the initial connecting segment of collecting tubules. With human liver, only the haematopoeitic cells of fetal liver reacted with all the antibodies.

scholarly journals The membrane domain of the human erythrocyte anion transport protein. Epitope mapping of a monoclonal antibody defines the location of a cytoplasmic loop near the C-terminus of the protein

1990 ◽  
Vol 272 (1) ◽  
pp. 265-268 ◽  
Author(s):  
S D Wainwright ◽  
W J Mawby ◽  
M J A Tanner
Keyword(s):  
Amino Acid ◽  
Human Erythrocyte ◽  
Protein Band ◽  
Anion Transport ◽  
Transport Protein ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
C Terminus ◽  
Murine Monoclonal Antibodies ◽  
Cytoplasmic Side

We have used synthetic peptides to study the location of the amino acid sequences in the human erythrocyte anion transport protein (band 3) which are recognized by four murine monoclonal antibodies, BRIC 130, 132, 154 and 155. These antibodies are known to react with epitopes in the protein which are on the cytoplasmic side of the membrane. The results suggest that the amino acid residues important for the reaction of BRIC 130 and BRIC 154/155 are located within amino acids 899-908 and 895-901 respectively in the cytoplasmic tail of the protein. The BRIC 132 epitope is located within amino acid residues 813-824. This is part of a surface loop in the protein which probably extends from residue 814 to residue 832 and is located on the cytoplasmic side of the membrane. These results provide direct evidence for the topographical location of a sequence in a poorly understood region of the protein.

scholarly journals The human erythrocyte anion-transport protein. Partial amino acid sequence, conformation and a possible molecular mechanism for anion exchange

1983 ◽  
Vol 213 (3) ◽  
pp. 577-586 ◽  
Author(s):  
C J Brock ◽  
M J A Tanner ◽  
C Kempf
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Mechanism ◽  
Anion Exchange ◽  
Human Erythrocyte ◽  
Exchange Process ◽  
Anion Transport ◽  
Transport Protein ◽  
British Library ◽  
Alpha Helices

The N-terminal 72 residues of an integral membrane fragment, P5, of the human erythrocyte anion-transport protein, which is known to be directly involved in the anion-exchange process, was shown to have the following amino acid sequence: Met-Val-Pro-Lys-Pro-Gln-Gly-Pro-Leu-Pro-Asn-Thr-Ala-Leu-Leu-Ser-Leu-Val-Leu-Met -Ala-Gly-Thr-Phe-Phe-Phe-Ala-Met-Met-Leu-Arg-Lys-Phe-Lys-Asn-Ser-Ser-Tyr-Phe-Pro-Gly-Lys-Leu-Arg-Arg-Val-Ile-Gly-Asp-Phe-Gly-Val-Pro-Ile-Ser-Ile-Leu-Ile-Met-Val-Leu-Val-Asp-Phe-Phe-Ile-Gln-Asp-Thr-Tyr-Thr-Gln- The structure of this fragment was analysed, with account being taken of the constraints that apply to the folding of integral membrane proteins and the topographical locations of various sites in the sequence. It was concluded that this sequence forms two transmembrane alpha-helices. These are probably part of a cluster of amphipathic transmembrane alpha-helices, which could comprise that part of the protein responsible for transport activity. The presently available evidence relating to the anion-exchange process was considered with the structural features noted in this study and a possible molecular mechanism is proposed. In this model the rearrangement of a network of intramembranous charged pairs mediates the translocation of an anion between anion-binding regions at each surface of the membrane, which are composed of clusters of positively charged amino acids. This model imposes a sequential exchange mechanism on the system. Supplementary material, including Tables and Figures describing the compositions of peptides determined by amino acid analysis and sequence studies, quantitative and qualitative data that provide a residue-by-residue justification for the sequence assignment and a description of modifications to and use of the solid-phase sequencer has been deposited as Supplementary Publication SUP 50123 (12 pages) with the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained as indicated in Biochem. J. (1983) 209, 5.

CLEAVAGE PATHWAY,AND SPECIFICITY OF LEUCOCYTE ELASTASE AS COMPARED TO PLASMIN DURING FIBRINOGEN DEGRADATION

1987 ◽  
Author(s):  
L Goretzki ◽  
E Miller ◽  
A Henschen
Keyword(s):  
Amino Acid ◽  
Time Course ◽  
Proteolytic Enzymes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecylsulfate ◽  
Reversed Phase ◽  
Cleavage Sites ◽  
Human Fibrinogen ◽  
Leucocyte Elastase ◽  
N Terminus

Plasmin and leucocyte elastase are regarded as the two medically most important fibrin(ogen)-degrading proteolytic enzymes. There is, however, a considerable difference in information available about the cleavage specificities and fragmentation pathways of these two enzymes. Degradation by plasmin has been studied already for a long time in great detail so that now the time course of the degradation, the cleavage sites and the functional properties of many fragments are well known. In contrast, relatively little is known about the degradation by leucocyte elastase, except that the overall cleavage pattern resembles that obtained with plasminIn this investigation the leucocyte elastase-mediated degradation of fibrinogen has been examined by means of proteinchemi-cal methods. Human fibrinogen was incubated with human enzyme material for various periods of time and at some different enzyme concentrations. The split products formed at the various stages were isolated in pure form by gel filtration followed by reversed-phase high-performance liquid chromatography. The fragments were identified by N-terminal amino acid sequence and amino acid composition. The course of the degradation was also monitored by sodium dodecylsulfate-polyacrylamide gel electrophoresis. All cleavage patterns were compared with the corresponding patterns from plasmic degradation. It could be confirmed that X-, D- and E-like fragments are formed also with elastase. However, several early elastolytic Aα-chain fragments are characteristically different from plasmic fragments. The previously identified N-terminal cleavage site in the Aα-chain, i.e. after position 21, was found to be the most important site in this region of fibrinogen. The very early degradation of the Aα-chain N-terminus by elastase is in strong contrast to the stability against plasmin. Several cleavage sites in N-terminal region of the Bβ-chain were observed, though the low amino acid specificity of elastase partly hampered the identification. The γ-chain N-terminus was found to be as highly stable towards elastase as towards plasmin. The results are expected to contribute to the understanding of the role of leucocyte elastase in pathophysiologic fibrino(geno)lysis

Conformation and stability of the anion transport protein of human erythrocyte membranes

Biochemistry ◽  
1985 ◽  
Vol 24 (12) ◽  
pp. 2843-2848 ◽  
Author(s):  
Kimio Oikawa ◽  
Debra M. Lieberman ◽  
Reinhart A. F. Reithmeier
Keyword(s):  
Human Erythrocyte ◽  
Anion Transport ◽  
Transport Protein ◽  
Erythrocyte Membranes ◽  
Human Erythrocyte Membranes

scholarly journals Functional analysis of the polar amino acid in TatA transmembrane helix

2021 ◽  
Author(s):  
Binhan Hao ◽  
Wenjie Zhou ◽  
Steven M Theg
Keyword(s):  
Amino Acid ◽  
Potential Role ◽  
Transmembrane Helix ◽  
Amino Acid Side Chain ◽  
Polar Amino Acid ◽  
Twin Arginine Translocation ◽  
N Terminus ◽  
Biochemical Approach ◽  
Folded Proteins ◽  
Highly Correlated

The twin-arginine translocation (Tat) pathway utilizes the proton-motive force (PMF) to transport folded proteins across cytoplasmic membranes in bacteria and archaea, as well as across the thylakoid membrane in plants and the inner membrane in mitochondria. In most species, the minimal components required for Tat activity consist of three subunits, TatA, TatB, and TatC. Previous studies have shown that a polar amino acid is present at the N-terminus of the TatA transmembrane helix (TMH) across many different species. In order to systematically assess the functional importance of this polar amino acid in the TatA TMH in Escherichia coli, a complete set of 19-amino-acid substitutions was examined. Unexpectedly, although being preferred overall, our experiments suggest that the polar amino acid is not necessary for a functional TatA. Hydrophobicity and helix stabilizing properties of this polar amino acid were found to be highly correlated with the Tat activity. Specifically, change in charge status of the amino acid side chain due to pH resulted in a shift in hydrophobicity, which was demonstrated to impact the Tat transport activity. Furthermore, a four-residue motif at the N-terminus of the TatA TMH was identified by sequence alignment. Using a biochemical approach, the N-terminal motif was found to be functionally significant, with evidence indicating a potential role in the preference for utilizing different PMF components. Taken together, these findings yield new insights into the functionality of TatA and its potential role in the Tat transport mechanism.

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.

The amino acid sequence of yeast phosphoglycerate mutase

1982 ◽  
Vol 215 (1198) ◽  
pp. 19-44 ◽  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Proteolytic Enzymes ◽  
Phosphoglycerate Mutase ◽  
Crystallographic Structure ◽  
X Ray ◽  
C Terminus ◽  
Detailed Interpretation ◽  
High Degree

The complete amino acid sequence of yeast phosphoglycerate mutase comprising 241 residues has been determined. The sequence was deduced from the two cyanogen bromide fragments, and from the peptides derived from these fragments after digestion by a number of proteolytic enzymes. Determination of this sequence now allows a detailed interpretation of the existing high-resolution X-ray crystallographic structure. A comparison of the sequence reported here with the sequences of peptides from phosphoglycerate mutases from other species, and with the sequence of erythrocyte diphosphoglycerate mutase, indicates that these enzymes have a high degree of structural homology. Autolysis of phosphoglycerate mutase by yeast extracts leads to the complete loss of mutase activity, and the formation of electrophoretically distinguishable forms (R. Sasaki, E. Sugimoto & H. Chiba, Archs Biochem. Biophys. 115, 53-61 (1966)). It is apparent from the amino acid sequence that these changes are due to the loss of an 8─12 residue peptide from the C-terminus.

scholarly journals DAPP1: a dual adaptor for phosphotyrosine and 3-phosphoinositides

1999 ◽  
Vol 342 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Simon DOWLER ◽  
Richard A. CURRIE ◽  
C. Peter DOWNES ◽  
Dario R. ALESSI
Keyword(s):  
Amino Acid ◽  
Sh2 Domain ◽  
Ph Domain ◽  
Phosphorylated Proteins ◽  
High Affinity ◽  
C Terminus ◽  
Acid Protein ◽  
N Terminus ◽  
Src Homology ◽  
Amino Acid Protein

We have identified a novel 280 amino acid protein which contains a putative myristoylation site at its N-terminus followed by an Src homology (SH2) domain and a pleckstrin homology (PH) domain at its C-terminus. It has been termed dual adaptor for phosphotyrosine and 3-phosphoinositides (DAPP1). DAPP1 is widely expressed and exhibits high-affinity interactions with PtdIns(3,4,5)P3 and PtdIns(3,4)P2, but not with other phospholipids tested. These observations predict that DAPP1 will interact with both tyrosine phosphorylated proteins and 3-phosphoinositides and may therefore play a role in regulating the location and/or activity of such proteins(s) in response to agonists that elevate PtdIns(3,4,5)P3 and PtdIns(3,4)P2.

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