Isopeptide synthesis

Y Sohma, M Sasaki, Y Hayashi, T Kimura, Y Kiso. Novel and efficient synthesis of difficult sequence-containing peptides through O-N intramolecular acyl migration reaction of O-acyl isopeptides. Chem Commun 124, 2004. 

Besides linear peptides, the substrate mimetics approach also enables synthesis of isopeptides [11], The prerequisite for this activity is use of an iso-type of sub-... 

Sohma Y, Sasaki M, Hayashi Y, Kimura T, Kiso Y. Design and synthesis of a novel water-soluble A(il-42 isopeptide an efficient strategy for the preparation of Alzheimer s disease-related peptide, Api-42, via O-N intramolecular acyl migration reaction. Tetrahedron Lett. 2004 45 5965-5968. 

Sohma Y, Kiso Y. Click peptides -chemical biology-oriented synthesis of Alzheimer s disease-related amyloid (> peptide (Afl) analogues based on the O-acyl isopeptide method . Chem-BioChem. 2006 7 1549-1557. 

In addition to their use in the in situ induction of conformational transitions, switch-peptides (O-acyl isopeptides) may serve as alternative solubilizing technique in peptide synthesis [207-214]. The elaboration of these concepts, notably the rational design of dynamic pharmacophores as new type of therapeutically useful compounds, is the subject of our current research. 

Example Synthesis of p-Amyloid (1-42) bytheo-Acyl Isopeptide Method... 

O-Acyl isopeptide method, an approach to the efHcient synthesis of peptides containing difficult sequences via the O-N... 

Depsipeptide SPPS methodology, a method for SPPS applicable to difficult sequences arising from aggregation phenomena. It relies on the synthesis of Ser or Thr isopeptide intermediates with a final 0-N acyl migration step. The principle is identical to the O-acyl isopeptide method, also termed click peptide or switch peptide method that were developed independently by different groups. It was, for example, successfully employed to synthesize the extremely difficult WWDomain FBP28 [I. Coin et al.,/. Org. Chem. 2006, 71, 6171]. 

Synthesis of ubiquitinated peptides and proteins with the native isopeptide linkage is very challenging. During the development of chemical ubiquitination methods, researchers frequently need to balance the necessity for nativity of the ubiquitin linkage against the labor requirements of the synthetic task. Many relatively simple methods to generate non-native or mimetic ubiquitin conjugates have therefore been developed. 

Isopeptide ligation is an alternative method for the synthesis of cysteine peptides via an intramolecular chemical ligation by an entropically favored mechanism. 5- to N-Acyl migration via various cyclic transition states was investigated by carrying out the ligation with mono-isopeptides under nucrowave irradiation (50°C, 50 W,... 

After synthesis in enterocytes (increasing in response to intestinal lipid absorption) Apo A-IV is secreted as a major apoprotein component of chylomicrons and is transported in the lymph ducts (for review see [17]). Upon entry into the blood plasma compartment, it rapidly dissociates from chylomicrons and is found in the lipoprotein-free plasma fraction. Weinberg und Spector [38] showed a difference in isoform distribution between lymph and plasma Apo A-IV. Treatment of lymph Apo A-IV with neuraminidase could not mimic the isopeptide change seen upon entry into the plasma compartment [38]. The authors showed that changes in Apo A-IV isoform... 

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