105 research outputs found
Pengaruh Suhu Pengukusan Terhadap Sifat Fisika Kimia Tepung Ikan Rucah
This research was aimed to determine the best steamed temperature and to determine the steamed effect on phsycochemical of trash fish. The research was conducted on June-July 2014 in fishery processing laboratory and fishery chemical laboratory Faculty of Fisheries and Marine Science Riau University, and this research was conducted also in food laboratory Bogor Agriculture Institute. Trash fish was obtained from Tanjung Beringin Village, Rampah - North Sumatera. The metode used in this research was completely randomized design (CRD) with 3 treatments of steamed temperature S1 (100 ΒΊC), S2 (90 ΒΊC) and S3 (80 ΒΊC).The results showed that the treatment S3 (80 ΒΊC) of steamed temperature was the best treatment with absorption 126.67, white degree 33.67, pH 6.41 and yield 16.90. Chemical characteristic for ash content 17.72 %, water content 7.51%, protein content 50.95%, fat content 7.70 % and crude fiber 4.22%
ΠΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΡΡΠ²ΠΎΡΠ΅Π½Π½Ρ ΠΊΠ°Π»ΡΠΊΡ[4]Π°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»-ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡΠ»ΠΎΡΠΈ Π· ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ ΡΠ° N-aΡΠ΅ΡΠΈΠ»-ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΡΠ΄ΠΎΠΌ
The Host-Guest complexation of calixarene hydroxymethylphosphonic acid with tryptophan and N-acetyltryptophan amide has been investigated by the RP HPLC method in H2O/MeCN (99/1) solution (column support Hypersil CN, UV-detector, Ξ» = 254 nm). Adsorption of calixarene hydroxymethylphosphonic acid on the Hypersil CN surface has been studied. It has been found that hydroxymethylphosphonic acid is characterized by reversible sorption on the Hypersil CN surface. The binding constants (KA = 23000 M-1 and 39000 M-1 for tryptophan and N-acetyltryptophan amide, respectively) of the supramolecular complexes have been calculated from the ratio between the capacity factors kβ of the Guest and the calixarene hydroxymethylphosphonic acid Host concentration in the mobile phase. The Gibbs free energies of the tryptophan and N-acetyltryptophan amide complexes are -24.84 and -26.15 kJ/mol, respectively. The molecular modelling of calixarene hydroxymethylphosphonic acid and its complexes with tryptophan and N-acetyltryptophan amide (Hyper Chem, version 8, force field PM3) has indicated that the complexes are stabilized by hydrogen bonds, electrostatic, Ο-Ο, and solvatophobic interactions. The geometric parameters of the energy minimized calixarene macrocycle and its complexes with tryptophan and N-acetyltryptophan amide have been calculated. According to the calculations it has been shown that the Host-Guest complexation does not change the flattened-cone conformation of calixarene. Finally, the inverse correlation has been found between the KA values of the complexes and the Log P values of the guest molecules.ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠ€ ΠΠΠΠ₯ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ ΠΏΡΠΎΡΠ΅ΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ ΡΠΈΠΏΠ° Π₯ΠΎΠ·ΡΠΈΠ½-ΠΠΎΡΡΡ ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ Ρ ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ ΠΈ N-aΡΠ΅ΡΠΈΠ»-ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΠΈΠ΄ΠΎΠΌ Π² ΡΠ°ΡΡΠ²ΠΎΡΠ΅ H2O/MeCN (99/1) (Π½Π°ΡΠ°Π΄ΠΊΠ° Hypersil CN, Π£Π€-Π΄Π΅ΡΠ΅ΠΊΡΠΎΡ, Ξ» = 254 Π½ΠΌ). ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ Ρ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΡΡ Ρ
ΡΠΎΠΌΠ°ΡΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ Π½Π°ΡΠ°Π΄ΠΊΠΈ Hypersil CN. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²Π°Ρ ΠΊΠΈΡΠ»ΠΎΡΠ° Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΠ΅ΡΡΡ ΠΎΠ±ΡΠ°ΡΠΈΠΌΠΎΠΉ ΡΠΎΡΠ±ΡΠΈΠ΅ΠΉ Π½Π° ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ Hypersil CN. ΠΠΎΠ½ΡΡΠ°Π½ΡΡ ΡΠ²ΡΠ·ΡΠ²Π°Π½ΠΈΡ ΡΡΠΏΡΠ°ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΡ
ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠ² (23000 M-1 ΠΈ 39000 M-1 Π΄Π»Ρ ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π° ΠΈ N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΠΈΠ΄Π°, ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎ) Π±ΡΠ»ΠΈ ΡΠ°ΡΡΡΠΈΡΠ°Π½Ρ ΠΈΠ· ΡΠΎΠΎΡΠ½ΠΎΡΠ΅Π½ΠΈΡ ΠΌΠ΅ΠΆ- Π΄Ρ ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠΎΠΌ Π΅ΠΌΠΊΠΎΡΡΠΈ kβ ΠΌΠΎΠ»Π΅ΠΊΡΠ»Ρ ΠΠΎΡΡΡ ΠΈ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΠ΅ΠΉ ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΒΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ Π₯ΠΎΠ·ΡΠΈΠ½Π° Π² ΠΏΠΎΠ΄Π²ΠΈΠΆΠ½ΠΎΠΉ ΡΠ°Π·Π΅. ΠΠ½Π°ΡΠ΅Π½ΠΈΡ ΡΠ²ΠΎΠ±ΠΎΠ΄Π½ΡΡ
ΡΠ½Π΅ΡΠ³ΠΈΠΉ ΠΠΈΠ±Π±ΡΠ° ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠ² ΠΊΠ°Π»ΠΈΠΊΡΠ°ΒΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ Ρ ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ ΠΈ N-aΡΠ΅ΡΠΈΠ»-ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΠΈΠ΄ΠΎΠΌ ΡΠΎΡΡΠ°Π²ΠΈΠ»ΠΈ -24.84 ΠΈ -26.15 ΠΊΠΠΆ/ΠΌΠΎΠ»Ρ, ΡΠΎΠΎΡΠ²Π΅ΡΡΡΠ²Π΅Π½Π½ΠΎ. ΠΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΠΎΠ΅ ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈ- ΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ ΠΈ Π΅Π΅ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠ² Ρ ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ ΠΈ N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΠΈΠ΄ΠΎΠΌ (Hyper Chem, Π²Π΅ΡΡΠΈΡ 8, ΡΠΈΠ»ΠΎΠ²ΠΎΠ΅ ΠΏΠΎΠ»Π΅ PM3). ΠΡΠΌΠ΅ΡΠ°Π΅ΡΡΡ, ΡΡΠΎ ΡΡΠΏΡΠ°ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΡΠ΅ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡ ΠΌΠΎΠ³ΡΡ ΡΡΠ°Π±ΠΈΠ»ΠΈΠ·ΠΈΡΠΎΠ²Π°ΡΡΡΡ Π²ΠΎΠ΄ΠΎΡΠΎΠ΄Π½ΡΠΌΠΈ ΡΠ²ΡΠ·ΡΠΌΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ»Π΅ΠΊΡΡΠΎΡΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ, Ο-Ο, ΠΈ ΡΠΎΠ»ΡΠ²Π°ΡΠΎΡΠΎΠ±Π½ΡΠΌΠΈ Π²Π·Π°ΠΈΠΌΠΎΠ΄Π΅ΠΉΡΡΠ²ΠΈΡΠΌΠΈ. Π Π°ΡΡΡΠΈΡΠ°Π½Ρ Π³Π΅ΠΎΠΌΠ΅ΡΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΡ ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ΅ΡΠΊΠΈ ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΡΡΡΡΠΊΡΡΡ ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π³ΠΈΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΠΉ ΠΊΠΈΡΠ»ΠΎΡΡ ΠΈ Π΅Π΅ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠ² Ρ ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ ΠΈ N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΠΈΠ΄ΠΎΠΌ. Π‘ΠΎΠ³Π»Π°ΡΠ½ΠΎ ΡΠ°ΡΡΠ΅ΡΠ°ΠΌ ΠΏΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΡΠΎ ΠΏΡΠΎΡΠ΅ΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΡ Π½Π΅ ΠΌΠ΅Π½ΡΠ΅Ρ ΠΊΠΎΠ½ΡΠΎΡΠΌΠ°ΡΠΈΡ ΠΌΠ°ΠΊΡΠΎΡΠΈΠΊΠ»ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΎΡΡΠΎΠ²Π° ΠΊΠ°Π»ΠΈΠΊΡΠ°ΡΠ΅Π½Π°. Π£ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΡΠΎ Π·Π½Π°ΡΠ΅Π½ΠΈΡ KA ΠΏΠΎΠ²ΡΡΠ°ΡΡΡΡ ΡΠΎ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠ΅ΠΌ Log P ΠΌΠΎΠ»Π΅ΠΊΡΠ» ΠΠΎΡΡΠ΅ΠΉ.ΠΠ΅ΡΠΎΠ΄ΠΎΠΌ ΠΠ€ ΠΠΠ Π₯ Π΄ΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½ΠΎ ΠΏΡΠΎΡΠ΅Ρ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΡΡΠ²ΠΎΡΠ΅Π½Π½Ρ ΡΠΈΠΏΡ ΠΠΎΡΠΏΠΎΠ΄Π°Ρ-ΠΡΡΡΡ ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈ- ΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡΠ»ΠΎΡΠΈ Π· ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ ΡΠ° N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΡΠ΄ΠΎΠΌ Ρ ΡΠΎΠ·ΡΠΈΠ½Ρ H2O/MeCN (99/1) (Π½Π°ΡΠ°Π΄ΠΊΠ° Hypersil CN, Π£Π€-Π΄Π΅ΡΠ΅ΠΊΡΠΎΡ, Ξ» = 254 Π½ΠΌ). ΠΠΎΡΠ»ΡΠ΄ΠΆΠ΅Π½ΠΎ Π²Π·Π°ΡΠΌΠΎΠ΄ΡΡ ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡΠ»ΠΎΡΠΈ Π· ΠΏΠΎΠ²Π΅ΡΡ
Π½Π΅Ρ Ρ
ΡΠΎΠΌΠ°ΡΠΎΠ³ΡΠ°ΡΡΡΠ½ΠΎΡ Π½Π°ΡΠ°Π΄ΠΊΠΈ Hypersil CN. ΠΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΎ, ΡΠΎ ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²Π° ΠΊΠΈΡΠ»ΠΎΡΠ° Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΡΡΡΡΡΡ ΠΎΠ±Π΅ΡΠ½Π΅Π½ΠΎΡ ΡΠΎΡΠ±ΡΡΡΡ Π½Π° ΠΏΠΎΠ²Π΅ΡΡ
Π½Ρ Hypersil CN. ΠΠΎΠ½- ΡΡΠ°Π½ΡΠΈ Π·Π²βΡΠ·ΡΠ²Π°Π½Π½Ρ ΡΡΠΏΡΠ°ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½ΠΈΡ
ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡΠ² (23000 M-1 Ρ 39000 M-1 Π΄Π»Ρ ΡΡΠΈΠΏΡΠΎΡΠ°Π½Ρ Ρ N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΡΠ΄Ρ, Π²ΡΠ΄ΠΏΠΎΠ²ΡΠ΄Π½ΠΎ) Π±ΡΠ»ΠΈ ΡΠΎΠ·ΡΠ°Ρ
ΠΎΠ²Π°Π½Ρ ΡΠ· ΡΠΏΡΠ²Π²ΡΠ΄Π½ΠΎΡΠ΅Π½Π½Ρ ΠΌΡΠΆ ΠΊΠΎΠ΅ΡΡΡΡΡΠ½ΡΠΎΠΌ ΡΠΌΠΊΠΎΡΡΡ kβ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΠΈ ΠΠΎΡΡΡ Ρ ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΡΡΡ ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡΠ»ΠΎΡΠΈ ΠΠΎΡΠΏΠΎΠ΄Π°ΡΡ Π² ΡΡΡ
ΠΎΠΌΡΠΉ ΡΠ°Π·Ρ. ΠΠ½Π°ΡΠ΅Π½Π½Ρ Π²ΡΠ»ΡΠ½ΠΈΡ
ΡΠ½Π΅ΡΠ³ΡΠΉ ΠΡΠ±Π±ΡΠ° ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡΠ² ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡΠ»ΠΎΡΠΈ Π· ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ Ρ N-aΡΠ΅- ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΡΠ΄ΠΎΠΌ ΡΠΊΠ»Π°Π΄Π°Ρ -24.84 Ρ -26.15 ΠΊΠΠΆ/ΠΌΠΎΠ»Ρ, Π²ΡΠ΄ΠΏΠΎΠ²ΡΠ΄Π½ΠΎ. ΠΠ΄ΡΠΉΡΠ½Π΅Π½ΠΎ ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½Π΅ ΠΌΠΎΠ΄Π΅Π»ΡΠ²Π°Π½Π½Ρ ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡΠ»ΠΎΡΠΈ Ρ ΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡΠ² Π· ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ Ρ N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΡΠ΄ΠΎΠΌ (Hyper Chem, Π²Π΅ΡΡΡΡ 8, ΡΠΈΠ»ΠΎΠ²Π΅ ΠΏΠΎΠ»Π΅ PM3). Π‘ΡΠΏΡΠ°ΠΌΠΎΠ»Π΅ΠΊΡΠ»ΡΡΠ½Ρ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΈ ΠΌΠΎΠΆΡΡΡ ΡΡΠ°Π±ΡΠ»ΡΠ·ΡΠ²Π°ΡΠΈΡΡ Π²ΠΎΠ΄Π½Π΅Π²ΠΈΠΌΠΈ Π·Π²βΡΠ·ΠΊΠ°ΠΌΠΈ, Π° ΡΠ°ΠΊΠΎΠΆ Π΅Π»Π΅ΠΊΡΡΠΎΡΡΠ°ΡΠΈΡΠ½ΠΈΠΌΠΈ, Ο-Ο, Ρ ΡΠΎΠ»ΡΠ²Π°ΡΠΎΡΠΎΠ±Π½ΠΈΠΌΠΈ Π²Π·Π°ΡΠΌΠΎΠ΄ΡΡΠΌΠΈ. Π ΠΎΠ·ΡΠ°Ρ
ΠΎΠ²Π°Π½Ρ Π³Π΅ΠΎΠΌΠ΅ΡΡΠΈΡΠ½Ρ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΈ ΡΠ½Π΅ΡΠ³Π΅ΡΠΈΡΠ½ΠΎ ΠΌΡΠ½ΡΠΌΡΠ·ΠΎΠ²Π°Π½ΠΈΡ
ΡΡΡΡΠΊΡΡΡ ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Π³ΡΠ΄ΡΠΎΠΊΡΠΈΠΌΠ΅ΡΠΈΠ»ΡΠΎΡΡΠΎΠ½ΠΎΠ²ΠΎΡ ΠΊΠΈΡ- Π»ΠΎΡΠΈ ΡΠ° ΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡΠ² Π· ΡΡΠΈΠΏΡΠΎΡΠ°Π½ΠΎΠΌ Ρ N-aΡΠ΅ΡΠΈΠ»ΡΡΠΈΠΏΡΠΎΡΠ°Π½Π°ΠΌΡΠ΄ΠΎΠΌ. ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ, ΡΠΎ Π·Π½Π°ΡΠ΅Π½Π½Ρ KA Π·ΡΠΎΡΒΡΠ°ΡΡΡ Π·Ρ Π·Π½ΠΈΠΆΠ΅Π½Π½ΡΠΌ Log P ΠΌΠΎΠ»Π΅ΠΊΡΠ» ΡΡΠ±ΡΡΡΠ°ΡΡΠ², Π° ΠΏΡΠΎΡΠ΅Ρ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠΎΡΡΠ²ΠΎΡΠ΅Π½Π½Ρ Π½Π΅ Π·ΠΌΡΠ½ΡΡ ΠΊΠΎΠ½ΡΠΎΡΠΌΠ°ΡΡΡ ΠΌΠ°ΠΊΡΠΎΡΠΈΠΊΠ»ΡΡΠ½ΠΎΠ³ΠΎ ΠΊΡΡΡΡΠΊΠ° ΠΊΠ°Π»ΡΠΊΡΠ°ΡΠ΅Π½Ρ
Non-coordinating anions assemble cyanine amphiphiles into ultra-small fluorescent nanoparticles
A non-coordinating anion, fluorinated tetraphenylborate, assembles specially designed cationic cyanine amphiphiles into 7β8 nm fluorescent nanoparticles that are >40-fold brighter than a single cyanine dye. This kind of anion, combining hydrophobic and electrostatic forces in aqueous media, constitutes promising building blocks in the self-assembly of functional nanomaterials
Intermolecular dark resonance energy transfer (DRET): Upgrading fluorogenic DNA sensing
The sensitivity of FRET-based sensing is usually limited by the spectral overlaps of the FRET donor and acceptor, which generate a poor signal-to-noise ratio. To overcome this limitation, a quenched donor presenting a large Stokes shift can be combined with a bright acceptor to perform Dark Resonance Energy Transfer (DRET). The consequent fluorogenic response from the acceptor considerably improves the signal-to-noise ratio. To date, DRET has mainly relied on a donor that is covalently bound to the acceptor. In this context, our aim was to develop the first intermolecular DRET pair for specific sensing of nucleic acid sequences. To this end, we designed DFK, a push-pull probe based on a fluorenyl Ο-platform that is strongly quenched in water. DFK was incorporated into a series of oligonucleotides and used as a DRET donor with Cy5-labeled complementary sequences. In line with our expectations, excitation of the dark donor in the double-labeled duplex switched on the far-red Cy5 emission and remained free of cross-excitation. The DRET mechanism was supported by time-resolved fluorescence measurements. This concept was then applied with binary probes, which confirmed the distance dependence of DRET as well as its potency in detecting sequences of interest with low background noise
Nucleic Acids Res
We have used surface plasmon resonance to investigate the nucleic acid binding properties of the core protein of hepatitis C virus, a disordered protein believed to chaperone the genomic RNA. It was previously shown that a peptide (peptide E) corresponding to the association of two basic clusters of core enhances the annealing and the dimerization of nucleic acid fragments derived from a stem loop (SL2) in the 3' untranslated region of the hepatitis C virus genome. However, strong aggregation of nucleic acids by core or peptide E in the excess of the latter precluded the characterization of their binding parameters up to now. By careful design of surface plasmon resonance experiments, we obtained accurate binding parameters for the interaction of peptide E with SL2-derived oligonucleotides of different lengths and sequences, in form of stem-loop, duplex or strand. Peptide E was found to bind in a salt dependent manner to all oligonucleotides assayed. Affinity data identify at least two binding modes, of which one is independent of sequence/structure, and the other is specific to the SL2 stem-loop fold. Stoichiometry data support a multi-motif binding model allowing formation of higher-order complexes. We propose that the modular binding mode demonstrated for structured RNA-binding proteins also applies to this disordered chaperone and is relevant to its activity
Wnt signaling is boosted during intestinal regeneration by a CD44-positive feedback loop
Enhancement of Wnt signaling is fundamental for stem cell function during intestinal regeneration. Molecular modules control Wnt activity by regulating signal transduction. CD44 is such a positive regulator and a Wnt target gene. While highly expressed in intestinal crypts and used as a stem cell marker, its role during intestinal homeostasis and regeneration remains unknown. Here we propose a CD44 positive-feedback loop that boosts Wnt signal transduction, thus impacting intestinal regeneration. Excision of Cd44 in Cd44;VillinCreER mice reduced Wnt target gene expression in intestinal crypts and affected stem cell functionality in organoids. Although the integrity of the intestinal epithelium was conserved in mice lacking CD44, they were hypersensitive to dextran sulfate sodium, and showed more severe inflammation and delayed regeneration. We localized the molecular function of CD44 at the Wnt signalosome, and identified novel DVL/CD44 and AXIN/CD44 complexes. CD44 thus promotes optimal Wnt signaling during intestinal regeneration
Nucleic Acids Res
The HIV-1 nucleocapsid protein (NCp7) is a nucleic acid chaperone required during reverse transcription. During the first strand transfer, NCp7 is thought to destabilize cTAR, the (-)DNA copy of the TAR RNA hairpin, and subsequently direct the TAR/cTAR annealing through the zipping of their destabilized stem ends. To further characterize the destabilizing activity of NCp7, we locally probe the structure and dynamics of cTAR by steady-state and time resolved fluorescence spectroscopy. NC(11-55), a truncated NCp7 version corresponding to its zinc-finger domain, was found to bind all over the sequence and to preferentially destabilize the penultimate double-stranded segment in the lower part of the cTAR stem. This destabilization is achieved through zinc-finger-dependent binding of NC to the G(10) and G(50) residues. Sequence comparison further revealed that C*A mismatches close to the two G residues were critical for fine tuning the stability of the lower part of the cTAR stem and conferring to G(10) and G(50) the appropriate mobility and accessibility for specific recognition by NC. Our data also highlight the necessary plasticity of NCp7 to adapt to the sequence and structure variability of cTAR to chaperone its annealing with TAR through a specific pathway
Photopolymerized micelles of diacetylene amphiphile: physical characterization and cell delivery properties:
A series of polydiacetylene (PDA) - based micelles were prepared from diacetylenic surfactant bearing polyethylene glycol, by increasing UV-irradiation times. These polymeric lipid micelles were analyzed by physicochemical methods, electron microscopy and NMR analysis. Cellular delivery of fluorescent dye suggests that adjusting the polymerization state is vital to reach the full in vitro potential of PDA-based delivery system
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