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since we have been talking about peptides what do you guys think of this?
I did take this from the site that sells the stuff so it could be a lil mis-leading?
PEGylated MGF (IGF-1Ec)
(MECHANO GROWTH FACTOR) - Produced in the USA
We are the first and only company with PEGylated MGF and all our peptides are synthesized in the USA.
PEGylated Mechano Growth Factor is a new and innovative form of MGF that outperforms natural MGF many times over. PEG stands for polyethylene glycol, a unique polymer that is non-ionic and soluble in water. By covalently bonding a PEG chain to a peptide you can expand the physical radius of the overall molecule, which creates a “shield” around the peptide and prevents proteases and antibodies from cleaving it and rendering it inactive. PEGylation also has various lengths (weights) and using a chain that is too large can block the binding of the peptide to its receptor. This, and the fact that MGF is a smaller peptide, is why we decided to use a smaller PEG chain and since d-arg MGF is insoluble in water the addition of a PEG chain is a positive feature to this peptide.
Commentary highlighted in green is to further explain the statements from the article and key points from the article are highlighted in red.......
The FASEB Journal express article 10.1096/fj.05-3786fje. Published online September 6, 2005
A strong neuroprotective effect of the autonomous Cterminal peptide of IGF-1 Ec (MGF) in brain ischemia
Joanna Dłużniewska,* Anna Sarnowska,† Małgorzata Beręsewicz,* Ian Johnson,‡Surjit K. S. Srai,§ Bala Ramesh,§ Geoffrey Goldspink,|| Dariusz C. Górecki,¶ and Barbara Zabłocka*
Peptide synthesis
The 24 amino acid peptide amide (NH2-YQPPSTNKNTKSQ(d)R(d)RKGSTFEEHK-NH2 corresponding to the shorter consensus mammalian sequence for the C-terminal MGF peptide was synthesized using the Fmoc protection strategy. The D-form of arginine was used for the synthesis instead of the naturally occurring L-form. The N terminus was modified by a PEG derivative (O’O-bis(2-aminopropyl)polyethylene glycol 1900) (Jeffamine) via a succinic acid bridge.................
Comments: Goldspink is the scientist that actually discovered MGF and for purposes specific to this study he uses MGF but instead of the human sequence which contains 3 arginines, they use the shorter consensus mamalian sequence containing 2 arginines. They removed the arginine at the 23rd position. Human form MGF has a third arginine at the 23rd position. They are also using the D-form of arginine to keep them from cleaving and makes it more stable.
Based on these analyses and taking into account the high degree of homology, we have generated a consensus sequence for the mammalian 24aa C-terminal peptides of the IGF-1 splice variant IGF-1Eb/Ec or MGF (Fig. 1B). This consensus sequence was used to prepare a synthetic, 24 amino acid long MGF C-terminal peptide. Based on the human sequence, this peptide contained two rather than three arginines (Fig. 1B). To increase the stability of the MGF peptide, which was found to be rapidly degraded in the serum or tissue fluids (Yang and Goldspink, unpublished), the D-form of arginine was used for synthesis instead of the naturally occurring Lform. Moreover, the N terminus of the peptide was PEGylated...................
Comments: As you can see proof here that plain MGF is not stable and must be PEGylated to stabilize.....from the mouth of Goldspink himself.
Such a small and biologically active molecule is a good candidate for development into a therapeutic modality. Indeed, we have shown here that C-terminal MGF peptide can be modified into a more stable and potentially targetable moiety by specific chemical modifications. In contrast, the recombinant full-length IGF-1, although neuroprotective in vitro, was found ineffective when delivered by intracarotid injection. It remains to be elucidated whether this disparity was due to different biological activities or resulted from the increased stability of the modified C-terminal MGF molecule. The difference in permeability through the blood-brain (BBB) barrier could also be a factor, but it has to be stressed that the PEGylated C-terminal MGF and recombinant IGF-1 have similar molecular size.
We demonstrate here the efficacy of the modified C-terminal MGF peptide administered as a single bolus injection intra-arterially. This suggests that the stabilized, pegylated peptide molecule was able to cross the BBB and penetrate into the neurones…………………..
Comments: As you can see clearly in red that PEGylation made the MGF peptide more stable and more targetable for development of a therapeutic modality for the pharmaceutical world.
I did take this from the site that sells the stuff so it could be a lil mis-leading?
PEGylated MGF (IGF-1Ec)
(MECHANO GROWTH FACTOR) - Produced in the USA
We are the first and only company with PEGylated MGF and all our peptides are synthesized in the USA.
PEGylated Mechano Growth Factor is a new and innovative form of MGF that outperforms natural MGF many times over. PEG stands for polyethylene glycol, a unique polymer that is non-ionic and soluble in water. By covalently bonding a PEG chain to a peptide you can expand the physical radius of the overall molecule, which creates a “shield” around the peptide and prevents proteases and antibodies from cleaving it and rendering it inactive. PEGylation also has various lengths (weights) and using a chain that is too large can block the binding of the peptide to its receptor. This, and the fact that MGF is a smaller peptide, is why we decided to use a smaller PEG chain and since d-arg MGF is insoluble in water the addition of a PEG chain is a positive feature to this peptide.
Commentary highlighted in green is to further explain the statements from the article and key points from the article are highlighted in red.......
The FASEB Journal express article 10.1096/fj.05-3786fje. Published online September 6, 2005
A strong neuroprotective effect of the autonomous Cterminal peptide of IGF-1 Ec (MGF) in brain ischemia
Joanna Dłużniewska,* Anna Sarnowska,† Małgorzata Beręsewicz,* Ian Johnson,‡Surjit K. S. Srai,§ Bala Ramesh,§ Geoffrey Goldspink,|| Dariusz C. Górecki,¶ and Barbara Zabłocka*
Peptide synthesis
The 24 amino acid peptide amide (NH2-YQPPSTNKNTKSQ(d)R(d)RKGSTFEEHK-NH2 corresponding to the shorter consensus mammalian sequence for the C-terminal MGF peptide was synthesized using the Fmoc protection strategy. The D-form of arginine was used for the synthesis instead of the naturally occurring L-form. The N terminus was modified by a PEG derivative (O’O-bis(2-aminopropyl)polyethylene glycol 1900) (Jeffamine) via a succinic acid bridge.................
Comments: Goldspink is the scientist that actually discovered MGF and for purposes specific to this study he uses MGF but instead of the human sequence which contains 3 arginines, they use the shorter consensus mamalian sequence containing 2 arginines. They removed the arginine at the 23rd position. Human form MGF has a third arginine at the 23rd position. They are also using the D-form of arginine to keep them from cleaving and makes it more stable.
Based on these analyses and taking into account the high degree of homology, we have generated a consensus sequence for the mammalian 24aa C-terminal peptides of the IGF-1 splice variant IGF-1Eb/Ec or MGF (Fig. 1B). This consensus sequence was used to prepare a synthetic, 24 amino acid long MGF C-terminal peptide. Based on the human sequence, this peptide contained two rather than three arginines (Fig. 1B). To increase the stability of the MGF peptide, which was found to be rapidly degraded in the serum or tissue fluids (Yang and Goldspink, unpublished), the D-form of arginine was used for synthesis instead of the naturally occurring Lform. Moreover, the N terminus of the peptide was PEGylated...................
Comments: As you can see proof here that plain MGF is not stable and must be PEGylated to stabilize.....from the mouth of Goldspink himself.
Such a small and biologically active molecule is a good candidate for development into a therapeutic modality. Indeed, we have shown here that C-terminal MGF peptide can be modified into a more stable and potentially targetable moiety by specific chemical modifications. In contrast, the recombinant full-length IGF-1, although neuroprotective in vitro, was found ineffective when delivered by intracarotid injection. It remains to be elucidated whether this disparity was due to different biological activities or resulted from the increased stability of the modified C-terminal MGF molecule. The difference in permeability through the blood-brain (BBB) barrier could also be a factor, but it has to be stressed that the PEGylated C-terminal MGF and recombinant IGF-1 have similar molecular size.
We demonstrate here the efficacy of the modified C-terminal MGF peptide administered as a single bolus injection intra-arterially. This suggests that the stabilized, pegylated peptide molecule was able to cross the BBB and penetrate into the neurones…………………..
Comments: As you can see clearly in red that PEGylation made the MGF peptide more stable and more targetable for development of a therapeutic modality for the pharmaceutical world.
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