- Influence of Sulfur-Containing Diamino Acid Structure on Covalently Crosslinked Copolypeptide Hydrogels
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Biologically occurring non-canonical di-α-amino acids were converted into new di-N-carboxyanhydride (di-NCA) monomers in reasonable yields with high purity. Five different di-NCAs were separately copolymerized with tert-butyl-l-glutamate NCA to obtain covalently crosslinked copolypeptides capable of forming hydrogels with varying crosslinker density. Comparison of hydrogel properties with residue structure revealed that different di-α-amino acids were not equivalent in crosslink formation. Notably, l-cystine was found to produce significantly weaker hydrogels compared to l-homocystine, l-cystathionine, and l-lanthionine, suggesting that l-cystine may be a sub-optimal choice of di-α-amino acid for preparation of copolypeptide networks. The di-α-amino acid crosslinkers also provided different chemical stability, where disulfide crosslinks were readily degraded by reduction, and thioether crosslinks were stable against reduction. This difference in response may provide a means to fine tune the reduction sensitivity of polypeptide biomaterial networks.
- Raftery, Eric D.,Gharkhanian, Eric G.,Ricapito, Nicole G.,McNamara,Deming, Timothy J.
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p. 3547 - 3553
(2018/09/25)
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- Design and synthesis of dimeric HIV-1 integrase inhibitory peptides
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Dimers of known HIV-1 integrase inhibitory hexapeptide H-His-Cys-Lys-Phe-Trp-Trp-NH2 containing different lengths of cross linkers in the place of cysteine residue, were designed, and synthesized. The inhibitory potency of these dimeric peptides is consistently higher than the lead hexapeptide. The dimeric peptide with djenkolic acid linker exhibited IC50 values of 5.3 and 6.5 μM, for 3′-end processing and strand transfer, respectively.
- Krajewski, Krzysztof,Long, Ya-Qiu,Marchand, Christophe,Pommier, Yves,Roller, Peter P.
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p. 3203 - 3205
(2007/10/03)
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- Syntheses of S-Substituted L-Homocysteine Derivatives by Cystathionine γ-Lyase of Streptomyces phaeochromogenes
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Cystationine γ-lyase from Streptomyces phaeochromogenes catalyzes not only the α,γ-elimination rection of L-cystathionine, but also the γ-replacement reaction of L-homoserine in the presence of thiol compounds.Substrates for the enzyme in the γ-replacement reaction were examined.It was found that D-cysteine, L- and D-homocysteine, and 3- and 2-mercaptopropionate served as preferable substrates in the γ-replacement reaction.D-Allocystathionine, L- and mesohomolanthionine, S-carboxyethyl-L-homocysteine and S-methylcarboxymethyl-L-homocysteine were enzymatically synthesized from L-homoserine and the corresponding thiol compounds.The thus synthesized S-substituted L-homocysteine derivatives were isolated from large scale reaction mixtures and identified physicochemically.
- Kanzaki, Hiroshi,Kobayashi, Michihiko,Nagasawa, Toru,Yamada, Hideaki
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p. 391 - 398
(2007/10/02)
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