12 research outputs found
Bioactivity of endostatin derived peptides and design of new potentially active units using molecular dynamics simulations
Studies on the Structure−Activity Relationship of Endostatin: Synthesis of Human Endostatin Peptides Exhibiting Potent Antiangiogenic Activities
Studies on umami taste. Synthesis and structure-activity relationship of purine-5'-nucleotides as potential flavor enhancer
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Specific recognition of ZNF217 and other zinc finger proteins at a surface groove of C-terminal binding proteins.
Numerous transcription factors recruit C-terminal binding protein (CtBP) corepressors. We show that the large zinc finger protein ZNF217 contacts CtBP. ZNF217 is encoded by an oncogene frequently amplified in tumors. ZNF217 contains a typical Pro-X-Asp-Leu-Ser (PXDLS) motif that binds in CtBP's PXDLS-binding cleft. However, ZNF217 also contains a second motif, Arg-Arg-Thr (RRT), that binds a separate surface on CtBP. The crystal structure of CtBP bound to an RRTGAPPAL peptide shows that it contacts a surface crevice distinct from the PXDLS binding cleft. Interestingly, both PXDLS and RRT motifs are also found in other zinc finger proteins, such as RIZ. Finally, we show that ZNF217 represses several promoters, including one from a known CtBP target gene, and mutations preventing ZNF217's contact with CtBP reduce repression. These results identify a new CtBP interaction motif and establish ZNF217 as a transcriptional repressor protein that functions, at least in part, by associating with CtBP
Specific Recognition of ZNF217 and Other Zinc Finger Proteins at a Surface Groove of C-Terminal Binding Proteins
Numerous transcription factors recruit C-terminal binding protein (CtBP) corepressors. We show that the large zinc finger protein ZNF217 contacts CtBP. ZNF217 is encoded by an oncogene frequently amplified in tumors. ZNF217 contains a typical Pro-X-Asp-Leu-Ser (PXDLS) motif that binds in CtBP's PXDLS-binding cleft. However, ZNF217 also contains a second motif, Arg-Arg-Thr (RRT), that binds a separate surface on CtBP. The crystal structure of CtBP bound to an RRTGAPPAL peptide shows that it contacts a surface crevice distinct from the PXDLS binding cleft. Interestingly, both PXDLS and RRT motifs are also found in other zinc finger proteins, such as RIZ. Finally, we show that ZNF217 represses several promoters, including one from a known CtBP target gene, and mutations preventing ZNF217's contact with CtBP reduce repression. These results identify a new CtBP interaction motif and establish ZNF217 as a transcriptional repressor protein that functions, at least in part, by associating with CtBP
New ACE-Inhibitory Peptides from Hemp Seed (<i>Cannabis sativa</i> L.) Proteins
A hemp
seed protein isolate, prepared from defatted hemp seed meals
by alkaline solubilization/acid precipitation, was subjected to extensive
chemical hydrolysis under acid conditions (6 M HCl). The resulting
hydrolysate was fractionated by semipreparative RP-HPLC, and the purified
fractions were tested as inhibitors of angiotensin converting enzyme
(ACE). Mono- and bidimensional NMR experiments and LC-MS analyses
led to the identification of four potentially bioactive peptides,
i.e. GVLY, IEE, LGV, and RVR. They were prepared by solid-phase synthesis,
and tested for ACE-inhibitory activity. The IC<sub>50</sub> values
were GVLY 16 ± 1.5 μM, LGV 145 ± 13 μM, and
RVR 526 ± 33 μM, confirming that hemp seed may be a valuable
source of hypotensive peptides