- How post-translational modifications influence amyloid formation: A systematic study of phosphorylation and glycosylation in model peptides
-
A reciprocal relationship between phosphorylation and O-glycosylation has been reported for many cellular processes and human diseases. The accumulated evidence points to the significant role these post-translational modifications play in aggregation and fibril formation. Simplified peptide model systems provide a means for investigating the molecular changes associated with protein aggregation. In this study, by using an amyloid-forming model peptide, we show that phosphorylation and glycosylation can affect folding and aggregation kinetics differently. Incorporation of phosphoserines, regardless of their quantity and position, turned out to be most efficient in preventing amyloid formation, whereas O-glycosylation has a more subtle effect. The introduction of a single βgalactose does not change the folding behavior of the model peptide, but does alter the aggregation kinetics in a site-specific manner. The presence of multiple galactose residues has an effect similar to that of phosphorylation.
- Broncel, Malgorzata,Falenski, Jessica A.,Wagner, Sara C.,Hackenberger, Christian P. R.,Koksch, Beate
-
-
Read Online
- Multiple glycosylation of de novo designed α-helical coiled coil peptides
-
The aim of this study was to investigate the influence of multiple O-glycosylation in α-helical coiled coil peptides on the folding and stability. For this purpose we systematically incorporated one to six β-galactose residues into the solvent exposed positions of a 26 amino acid long coiled coil helix. Surprisingly, circular dichroism spectroscopy showed no unfolding of the coiled coil structure for all glycopeptides. Thermally induced denaturations reveal a successive but relative low destabilization of the coiled coil structure upon introduction of β-galactose residues. These first results indicate that O-glycosylation of the glycosylated variants is easily tolerated by this structural motif and pave the way for further functional studies.
- Falenski, Jessica A.,Gerling, Ulla I.M.,Koksch, Beate
-
-
Read Online
- Effects of Glycosylation and d -Amino Acid Substitution on the Antitumor and Antibacterial Activities of Bee Venom Peptide HYL
-
Glycosylation is a promising strategy for modulating the physicochemical properties of peptides. However, the influence of glycosylation on the biological activities of peptides remains unknown. Here, we chose the bee venom peptide HYL as a model peptide and 12 different monosaccharides as model sugars to study the effects of glycosylation site, number, and monosaccharide structure on the biochemical properties, activities, and cellular selectivities of HYL derivatives. Some analogues of HYL showed improvement not only in cell selectivity and proteolytic stability but also in antitumor and antimicrobial activity. Moreover, we found that the helicity of glycopeptides can affect its antitumor activity and proteolytic stability, and the α-linked d-monosaccharides can effectively improve the antitumor activity of HYL. Therefore, it is possible to design peptides with improved properties by varying the number, structure, and position of monosaccharides. What's more, the glycopeptides HYL-31 and HYL-33 show a promising prospect for antitumor and antimicrobial drugs development, respectively. In addition, we found that the d-lysine substitution strategy can significantly improve the proteolytic stability of HYL. Our new approach provides a reference or guidance for the research of novel antitumor and antimicrobial peptide drugs.
- Wu, Ming-Hao,Ai, Su,Chen, Qing,Chen, Xiang-Yan,Li, Hong-Jin,Li, Yu-Lei,Zhao, Xia
-
p. 2293 - 2302
(2020/11/26)
-
- Facile synthesis of glycosylated Fmoc amino acid building blocks assisted by microwave irradiation
-
The synthesis of glycosylated Fmoc amino acids by reaction of mono- and disaccharide peracetates with Fmoc amino acids having free carboxyl groups was rapidly promoted by Lewis acids (SnCl4, BF3·Et 2O) under microwave irradiation. The products are useful building blocks for the synthesis of glycopeptides.
- Yao, Nianhuan,Fung, Gabriel,Malekan, Hamed,Ye, Long,Kurth, Mark J.,Lam, Kit S.
-
experimental part
p. 2277 - 2281
(2010/11/19)
-
- Carbohydrate-π interactions: What are they worth?
-
Protein-carbohydrate interactions play an important role in many biologically important processes. The recognition is mediated by a number of noncovalent interactions, including an interaction between the α-face of the carbohydrate and the aromatic side chain of the protein. To elucidate this interaction, it has been studied in the context of a β-hairpin in aqueous solution, in which the interaction can be investigated in the absence of other cooperative noncovalent interactions. In this β-hairpin system, both the aromatic side chain and the carbohydrate were varied in an effort to gain greater insight into the driving force and magnitude of the carbohydrate-π interaction. The magnitude of the interaction was found to vary from -0.5 to -0.8 kcal/mol, depending on the nature of the aromatic ring and the carbohydrate. Replacement of the aromatic ring with an aliphatic group resulted in a decrease in interaction energy to -0.1 kcal/mol, providing evidence for the contribution of CH-π interactions to the driving force. These findings demonstrate the significance of carbohydrate-π interactions within biological systems and also their utility as a molecular recognition element in designed systems.
- Laughrey, Zachary R.,Kiehna, Sarah E.,Riemen, Alex J.,Waters, Marcey L.
-
supporting information; experimental part
p. 14625 - 14633
(2009/02/08)
-
- Studies toward the site specific incorporation of sugars into proteins: Synthesis of glycosylated aminoacyl-tRNAs
-
A series of glycosylated serine derivatives was synthesized from peracetylated sugars and Fmoc-protected serine; these were chemically esterified with the tris-(tetrabutylammonium) salt of pdCpA. The fully protected and deprotected glycosylated aminoacyl pdCpAs were ligated enzymatically to an abbreviated tRNA (tRNA-COH) to provide the title compounds that are key intermediates in the elaboration of glycoproteins using readthrough of a nonsense codon.
- Fahmi, Nour Eddine,Golovine, Serguei,Wang, Bixun,Hecht, Sidney M.
-
p. 149 - 164
(2007/10/03)
-
- Iodine and its interhalogen compounds: versatile reagents in carbohydrate chemistry. XIV. Glycosylated amino acid synthesis
-
A practical procedure for glycosylated amino acid synthesis using iodine-promoted glycosylation of various protected serine and threonine with a selection of thioglycoside and glycosyl halide donors is described.
- Kartha, K. P. Ravindranathan,Ballell, Lluis,Bilke, Julia,McNeil, Michael,Field, Robert A.
-
p. 770 - 772
(2007/10/03)
-
- Solid phase synthesis of O-glycoopioid peptides related to dermorphin
-
Glycosylation of Fmoc-hydroxyamino acids with β-D-glucose pentaacetate has been carried out in the presence of several Lewis acids and BF3.Et2O has been found to be the most suitable one. Thus, 2,3,4,6-tetra-O-acetyl-β-D-glycopyranosyl derivatives of Fmoc-Ser/Thr/Tyr are prepared in a single step in reasonably good yields and high purity. The O-glycosylated derivatives are then converted to their corresponding trichlorophenyl esters for use in the solid phase synthesis of five glycoopioid peptides related to dermorphin. The effect of glycosylation on biological activity of dermorphin has been studied. Among the peptides synthesized, [Tyr(β-D-Glc)5]dermorphin and [Ser(β-D-Glc)5, Tyr7)]dermorphin exhibit considerable analgesic activity of about 80-90% compared to morphine and antidiarrhoeal activity of about 50% compared to dermorphin.
- Sivanandaiah,Suresh Babu,Shankaramma
-
p. 760 - 767
(2007/10/03)
-
- Preparation of Building Blocks for Glycopeptide Synthesis by Glycosylation of Fmoc Amino Acids Having Unprotected Carboxyl Groups
-
Nα-Fmoc amino acids with an unprotected α-carboxyl group have been glycosylated with carbohydrate 1,2-trans peracetates using Lewis acids as promoters.Aliphatic and phenolic O- and S-glycosides of amino acids, with a 1,2-trans anomeric configuration, were obtained as products in 34-65percent yields.The glycosylated building blocks have the protective groups of choice (i.e.O-acetyl and Nα-Fmoc) for direct use in stepwise synthesis of glycopeptides.The starting materials are readily available and the method does not require an extensive experience in synthetic carbohydrate chemistry.
- Salvador, Lourdes A.,Eloffson, Mikael,Kihlberg, Jan
-
p. 5643 - 5656
(2007/10/02)
-
- Building blocks for glycopeptide synthesis: Glycosylation of 3-Mercaptopropionic acid and Fmoc amino acids with unprotected carboxyl groups
-
3-Mercaptopropionic acid and Fmoc amino acids, having unprotected carboxyl groups, were glycosylated with sugar 1,2-trans-acetates in 90 and 53-65% yields, respectively, under lewis acid promotion. The synthesis of a neoglycopeptide illustrates the use of the building blocks in solid phase peptide synthesis.
- Elofsson,Walse,Kihlberg
-
p. 7613 - 7616
(2007/10/02)
-
- Improved method for the synthesis of o-glycosylated fmoc amino acids to be used in solid-phase glycopeptide synthesis (Fmoc = fluoren-9-ylmethoxycarbonyl)
-
The building blocks O1-(2,3,4,6-tetra-O-acetyl-β-D- galactopyranosyl)-Nα(fluoren-9-ylmethoxycarbonyl)serine (5)and O 1-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl) -Nα-(fluoren-9-ylmethoxycarbonyl)threonine (6) for use in solid-phase glycopeptide synthesis can be obtained via their ally esters by mild treatment with tetrakis(triphenylphosphine)palladium(0) and tributyltin hydride with no Fmoc elimination or sugar cleavage or anomerization.
- De La Torre, Beatriz G.,Torres, Josep L.,Bardaji, Eduard,Clapes, Pere,Xaus, Nuria,Jorba, Xavier,Calvet, Silvia,Albericio, Fernando,Valencia, Gregorio
-
p. 965 - 967
(2007/10/02)
-
- SYNTHESIS OF THE GLYCOTRIPEPTIDE ALANYL-(O-β-D-GALACTOPYRANOSYLSERYL)-ALANINE USING (9-FLUORENYLMETHOXY)CARBONYL AND ESTERS OF 2-(HYDROXYMETHYL)-9,10-ANTHRAQUINONE AS TEMPORARY PROTECTING GROUPS.
-
The cesium salts of N-((9-fluorenylmethoxy)carbonyl)-L-serine (Fmoc-Ser, 1a) abd -L-threonine (Fmoc-Thr, 1b) were treated with 2-(bromomethyl)-9,10-anthraquinone (Maq-Br), yielding Fmoc-Ser-OMaq (2a, 79percent) and Fmoc-Thr-OMaq (2b, 74percent).HgBr2-catalyzed glycosylation with 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide gave Fmoc-Ser(Ac4βGal)-OMaq (3a, 89percent) and Fmoc-Thr(Ac4βGal)-OMaq (13b, 53percent).Fmoc-Ser(Ac4βGal)-OH (4), obtained by reaction of 1a with Na2S2O4 (88percent), was condensed with H-Ala-OMaq using the DCC/HOBt method (83percent).The Fmoc-Ser(Ac4βGal)-Ala-OMaq (5), thus obtained, was Nα-deprotected with morpholine and coupled with Fmoc-Ala using water soluble carbodiimide in the presence of HOBt to yield Fmoc-Ala-Ser(Ac4βGal)-Ala-OMaq (6, 59percent).The fully deprotected glycotripeptide (8) was obtained from 6 by successive treatment with Na2S2O4, morpholine and hydrazine hydrate (81percent).The compounds 3a, 6 and 8 were characterized using correlated 300 MHz 1H NMR spectroscopy (2D-COSY).
- Hoogerhout, P.,Guis, C. P.,Erkelens, C.,Bloemhoff, W.,Kerling, K. E. T.,Boom, J. H. van
-
-