scholarly journals The HP1 chromo shadow domain binds a consensus peptide pentamer

2000 ◽  
Vol 10 (1) ◽  
pp. 27-30 ◽  
Author(s):  
James F. Smothers ◽  
Steven Henikoff
Keyword(s):  
Consensus Peptide ◽  
Chromo Shadow Domain

scholarly journals Δομικός και λειτουργικός χαρακτηρισμός χρωμοπρωτεϊνών

2007 ◽  
Author(s):  
Δημοσθένης Μπόλης
Keyword(s):  
Chromo Shadow Domain

Το chromodomain έχει αναδειχθεί βιβλιογραφικά σε κεντρικό "παίκτη" στην αναδιαμόρφωση της χρωματίνης, ο ρόλος του όμως έχει περιορισθεί στην αναγνώριση μετά-μεταφραστικών σημάτων με τη μορφή ομοιοπολικών τροποποιήσεων επί των ιστονικών ουρών. Με χρήση βιοχημικών τεχνικώνεπιβεβαιώθηκε η πρόσδεση του c2 απ' ευθείας σε μόρια DNA, ενώ για πρώτη φορά δείχθηκε συγγένεια και προς την ιστόνη Η3. Προκειμένου να προσδιοριστεί πώς το c2 διαφοροποιείται ώστε να εμφανίζει συγγένεια για έναν τόσο χημικά διαφορετικό από τις ιστόνες προσδέτη όπως είναι το DNA, επιχειρήθηκε η επίλυση της τριτοταγούς δομής του με NMR. Ο ολιγομερισμός του απομονωμένου c2 τιθασεύτηκε μερικώς με χρήση τεχνικών Μοριακής Βιολογίας σε βαθμό που νακαθίσταται εφικτός ο προσδιορισμός της τριτοταγούς δομής με NMR. Ανάλυση της δομής έδειξε ότι το c2 είναι μια συμπαγής, καλά αναδιπλωμένη πρωτεΐνη, αποτελούμενη από μια β- πτυχωτή επιφάνεια και μια καρβοξυτελική α-έλικα, που είναι διατεταγμένα στο χώρο, έτσι ώστε να σχηματίζουν τη χαρακτηριστική α+β αναδίπλωση των chromodomain (α+β chromodomain fold). Ο χαρακτηριστικός για τα chromodomain αρωματικός κλωβός υφίσταται μεν στην επιφάνεια του c2,διαφέρει όμως από αυτόν των "προτύπων" μελών της οικογένειας των chromodomain. Αποκαλύφθηκε επιπλέον μια ανισομερής κατανομή φορτίου στην επιφάνεια του c2, η οποία επιτρέπει την ύπαρξη θετικά φορτισμένων όψεων του μορίου, γεγονός μη αναμενόμενο δεδομένου του θεωρητικού ισοηλεκτρικού του σημείου (pI=4.90). Τα χαρακτηριστικά της επιφάνειας του θα επέτρεπαν τη συζευγμένη πρόσδεση νουκλεοσωμικού DNA και ιστονών στο c2, καθιστώντας τοτο μόνο -έως τη συγγραφή αυτής της διατριβής- chromodomain που αλληλεπιδρά με περισσότερα του ενός νουκλεοσωμικά συστατικά. Τέλος ο βιοφυσικός, βιοχημικός και δομικός χαρακτηρισμός του c2 προδίδει τον υβριδικό του χαρακτήρα μεταξύ του chromo- και του chromo-shadow domain.

scholarly journals From Consensus Sequence Peptide to High Affinity Ligand, a “Library Scan” Strategy

2001 ◽  
Vol 276 (15) ◽  
pp. 12235-12240 ◽  
Author(s):  
Ren-Hwa Yeh ◽  
Tae Ryong Lee ◽  
David S. Lawrence
Keyword(s):  
Consensus Sequence ◽  
Sh2 Domain ◽  
Amino Acid Sequences ◽  
Parallel Synthesis ◽  
Intact Protein ◽  
High Affinity ◽  
Affinity Ligand ◽  
Combinatorial Peptide Libraries ◽  
Synthesis Strategy ◽  
Consensus Peptide

A wide variety of proteins have been shown to recognize and bind to specific amino acid sequences on other proteins. These sequences can be readily identified using combinatorial peptide libraries. However, peptides containing these preferred sequences (“consensus sequence peptides”) typically display only modest affinities for the consensus sequence-binding site on the intact protein. In this report, we describe a parallel synthesis strategy that transforms consensus sequence peptides into high affinity ligands. The work described herein has focused on the Lck SH2 domain, which binds the consensus peptide acetyl-Tyr(P)-Glu-Glu-Ile-amide with aKDof 1.3 μm. We employed a strategy that creates a series of spatially focused libraries that challenge specific subsites on the target protein with a diverse array of functionality. The final lead compound identified in this study displayed a 3300-fold higher affinity for the Lck SH2 domain than the starting consensus sequence peptide.

scholarly journals Rapid Prescreening for Antiviral Agents against HIV-1 Based on Their Inhibitory Activity in Site-Directed Immunoassays. Approaches Applicable to Epidemic HIV-1 Strains

1993 ◽  
Vol 4 (4) ◽  
pp. 207-214 ◽  
Author(s):  
A. R. Neurath ◽  
N. Strick ◽  
S. Jiang
Keyword(s):  
Antiviral Activity ◽  
North American ◽  
Antiviral Agents ◽  
Envelope Glycoproteins ◽  
V3 Loop ◽  
European North ◽  
Consensus Peptide ◽  
Antiviral Chemotherapy ◽  
Anti Hiv ◽  
Hiv 1

Several compounds, including the triphenylmethane derivative aurintricarboxylic acid (ATA) and porphyrins, were reported to inhibit the binding of anti-V3 loop-specific antibodies to the V3 loop of gp120 from HIV-1 III-B and to have antiviral activity, probably due to interference with the biological function of the V3 loop. However, these compounds can be applied to antiviral chemotherapy only if they interact with envelope glycoproteins from a multitude of epidemic HIV-1 strains and inhibit their replication. Since recombinant envelope glycoproteins, synthetic peptides and anti-V3 monoclonal antibodies may not be available for these HIV-1 strains, alternative assays are needed to prescreen different compounds for potential antiviral activity against these viruses. Results presented here indicate that: (1) virions of HIV-1 MN, most closely related to primary HIV-1 isolates from European and North American countries, and human anti-HIV-1 antibodies, can also be used for rapid prescreening of antiviral agents, (2) compounds with antiviral activity against HIV-1 MN, discerned by site-directed immunoassays, inhibited the reaction of human anti-HIV-1 with a V3 loop consensus peptide corresponding to European/North American HIV-1 isolates, and (3) meso-tetra (4-carboxyphenyl) porphine (MTCPP), one of the most potent inhibitors of HIV-1 replication selected on the basis of site-directed immunoassays, preferentially attached to the V3 loop of gp120.

Identification, synthesis and properties of a consensus peptide recognized by a monoclonal antibody directed to various type I cytokine receptors

Life Sciences ◽  
2007 ◽  
Vol 81 (7) ◽  
pp. 553-559 ◽  
Author(s):  
Carlos G. Belloc ◽  
Silvia A. Longhi ◽  
Clara Peña ◽  
Viviana A. Blank ◽  
Marta E. Miranda ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cytokine Receptors ◽  
Type I ◽  
Consensus Peptide

scholarly journals Dimerisation of a chromo shadow domain and distinctions from the chromodomain as revealed by structural analysis

2000 ◽  
Vol 10 (9) ◽  
pp. 517-525 ◽  
Author(s):  
Nathan P. Cowieson ◽  
Janet F. Partridge ◽  
Robin C. Allshire ◽  
Paul J. McLaughlin
Keyword(s):  
Structural Analysis ◽  
Chromo Shadow Domain

scholarly journals Direct Interaction between DNA Methyltransferase DIM-2 and HP1 Is Required for DNA Methylation in Neurospora crassa

2008 ◽  
Vol 28 (19) ◽  
pp. 6044-6055 ◽  
Author(s):  
Shinji Honda ◽  
Eric U. Selker
Keyword(s):  
Dna Methylation ◽  
Neurospora Crassa ◽  
Dna Methyltransferase ◽  
Direct Interaction ◽  
Stable Complex ◽  
Heterochromatin Protein 1 ◽  
Heterochromatin Protein ◽  
Chromo Shadow Domain ◽  
Two Hybrid

ABSTRACT DNA methylation is involved in gene silencing and genomic stability in mammals, plants, and fungi. Genetics studies of Neurospora crassa have revealed that a DNA methyltransferase (DIM-2), a histone H3K9 methyltransferase (DIM-5), and heterochromatin protein 1 (HP1) are required for DNA methylation. We explored the interrelationships of these components of the methylation machinery. A yeast two-hybrid screen revealed that HP1 interacts with DIM-2. We confirmed the interaction in vivo and demonstrated that it involves a pair of PXVXL-related motifs in the N-terminal region of DIM-2 and the chromo shadow domain of HP1. Both regions are essential for proper DNA methylation. We also determined that DIM-2 and HP1 form a stable complex independently of the trimethylation of histone H3K9, although the association of DIM-2 with its substrate sequences depends on trimethyl-H3K9. The DIM-2/HP1 complex does not include DIM-5. We conclude that DNA methylation in Neurospora is largely or exclusively the result of a unidirectional pathway in which DIM-5 methylates histone H3K9 and then the DIM-2/HP1 complex recognizes the resulting trimethyl-H3K9 mark via the chromo domain of HP1.

scholarly journals Tolerogenic Treatment of Lupus Mice with Consensus Peptide Induces Foxp3-Expressing, Apoptosis-Resistant, TGFβ-Secreting CD8+ T Cell Suppressors

2005 ◽  
Vol 175 (11) ◽  
pp. 7728-7737 ◽  
Author(s):  
Bevra H. Hahn ◽  
Ram Pyare Singh ◽  
Antonio La Cava ◽  
Fanny M. Ebling
Keyword(s):  
T Cell ◽  
Cd8 T Cell ◽  
Consensus Peptide
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