eukaryotes eg protein degradation and DNA repair. 1 Ubiquitination is a reversible posttranslatio... more eukaryotes eg protein degradation and DNA repair. 1 Ubiquitination is a reversible posttranslational modification wherein the removal of the ubiquitin (Ub) molecule is achieved by a family of enzymes known as deubiquitinases (DUBs). Approximately 100 ...
Ubiquitination-the attachment of ubiquitin to a protein target-is involved in a wide range of cel... more Ubiquitination-the attachment of ubiquitin to a protein target-is involved in a wide range of cellular processes in eukaryotes. This dynamic posttranslational modification utilizes three enzymes to link, through an isopeptide bond, the C-terminal Gly of ubiquitin to the lysine side chain from a protein target. Progress in the field aiming at deciphering the role of ubiquitination in biological processes has been very dependent on the discovery of the enzymatic machinery, which is known to be very specific to each protein target. Chemical approaches offer a complementary route to the biochemical methods to construct these conjugates in vitro in order to assist in unraveling the role of ubiquitination on protein function. Herein is presented a novel method for the rapid synthesis of ubiquitinated peptides employing solid-phase peptide to generate the critical isopeptide linkage. Using these tools, several ubiquitinated peptides derived from known ubiquitinated proteins were prepared. Among them is the ubiquitinated C-terminal fragment of H2B, which can be used in the synthesis of monoubiquitinated H2B. For the first time, we systematically assessed the effect of the length of the ubiquitinated peptides on the UCH-L3 activity and found that peptides of up to ∼20 residues are preferred substrates.
Kumar, KSA, Bavikar, SN, Spasser, L., Moyal, T., Ohayon, S. and Brik, A.(2011), Total Chemical Sy... more Kumar, KSA, Bavikar, SN, Spasser, L., Moyal, T., Ohayon, S. and Brik, A.(2011), Total Chemical Synthesis of a 304 Amino Acid K48-Linked Tetraubiquitin Protein. Angewandte Chemie International Edition, 50: 61376141. doi: 10.1002/anie. 201101920
Ubiquitination is one of the most utilized posttranslational modifications in eukaryotes and is i... more Ubiquitination is one of the most utilized posttranslational modifications in eukaryotes and is involved in a wide range of cellular processes, but is mostly known as a signal for proteasomal degradation. Recently, it has become clear that the ubiquitin signal is far more complex and is dictated by the ubiquitin component and the substrate. The remarkable diversity of the ubiquitin signaling process has triggered an incredible amount of effort to investigate the role of ubiquitination on biological processes. However, despite more than three decades of studies, several important questions remain unanswered. A major hurdle is the inability to obtain homogeneous ubiquitin bioconjugates in sufficient amounts from cells or by application of the enzymatic machinery. Recent breakthroughs in chemical and semisynthetic strategies, however, offer solutions to these challenges. In this Review, we survey the fundamental biological aspects of the ubiquitin signal and present the emerging non-enzymatic approaches for overcoming these obstacles.
Side-chain assisted ligation is an auxiliary-mediated ligation strategy in which a thiol bearing ... more Side-chain assisted ligation is an auxiliary-mediated ligation strategy in which a thiol bearing cyclohexane or cyclopentane is attached to the side-chain of Asp, Glu, Ser or Thr to function in a similar manner to Cys in a native chemical ligation. Following the ligation ...
eukaryotes eg protein degradation and DNA repair. 1 Ubiquitination is a reversible posttranslatio... more eukaryotes eg protein degradation and DNA repair. 1 Ubiquitination is a reversible posttranslational modification wherein the removal of the ubiquitin (Ub) molecule is achieved by a family of enzymes known as deubiquitinases (DUBs). Approximately 100 ...
Ubiquitination-the attachment of ubiquitin to a protein target-is involved in a wide range of cel... more Ubiquitination-the attachment of ubiquitin to a protein target-is involved in a wide range of cellular processes in eukaryotes. This dynamic posttranslational modification utilizes three enzymes to link, through an isopeptide bond, the C-terminal Gly of ubiquitin to the lysine side chain from a protein target. Progress in the field aiming at deciphering the role of ubiquitination in biological processes has been very dependent on the discovery of the enzymatic machinery, which is known to be very specific to each protein target. Chemical approaches offer a complementary route to the biochemical methods to construct these conjugates in vitro in order to assist in unraveling the role of ubiquitination on protein function. Herein is presented a novel method for the rapid synthesis of ubiquitinated peptides employing solid-phase peptide to generate the critical isopeptide linkage. Using these tools, several ubiquitinated peptides derived from known ubiquitinated proteins were prepared. Among them is the ubiquitinated C-terminal fragment of H2B, which can be used in the synthesis of monoubiquitinated H2B. For the first time, we systematically assessed the effect of the length of the ubiquitinated peptides on the UCH-L3 activity and found that peptides of up to ∼20 residues are preferred substrates.
Kumar, KSA, Bavikar, SN, Spasser, L., Moyal, T., Ohayon, S. and Brik, A.(2011), Total Chemical Sy... more Kumar, KSA, Bavikar, SN, Spasser, L., Moyal, T., Ohayon, S. and Brik, A.(2011), Total Chemical Synthesis of a 304 Amino Acid K48-Linked Tetraubiquitin Protein. Angewandte Chemie International Edition, 50: 61376141. doi: 10.1002/anie. 201101920
Ubiquitination is one of the most utilized posttranslational modifications in eukaryotes and is i... more Ubiquitination is one of the most utilized posttranslational modifications in eukaryotes and is involved in a wide range of cellular processes, but is mostly known as a signal for proteasomal degradation. Recently, it has become clear that the ubiquitin signal is far more complex and is dictated by the ubiquitin component and the substrate. The remarkable diversity of the ubiquitin signaling process has triggered an incredible amount of effort to investigate the role of ubiquitination on biological processes. However, despite more than three decades of studies, several important questions remain unanswered. A major hurdle is the inability to obtain homogeneous ubiquitin bioconjugates in sufficient amounts from cells or by application of the enzymatic machinery. Recent breakthroughs in chemical and semisynthetic strategies, however, offer solutions to these challenges. In this Review, we survey the fundamental biological aspects of the ubiquitin signal and present the emerging non-enzymatic approaches for overcoming these obstacles.
Side-chain assisted ligation is an auxiliary-mediated ligation strategy in which a thiol bearing ... more Side-chain assisted ligation is an auxiliary-mediated ligation strategy in which a thiol bearing cyclohexane or cyclopentane is attached to the side-chain of Asp, Glu, Ser or Thr to function in a similar manner to Cys in a native chemical ligation. Following the ligation ...
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