Infrared spectroscopic study of the secondary structure of melittin in water, 2-chloroethanol, and phospholipid bilayer dispersions

Lavialle, Françoise; Adams, Ralph G.; Levin, Ira W.

doi:10.1021/bi00539a006

Cited by 89 publications

(53 citation statements)

References 38 publications

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“…Alcohol-dependent helix formation in melittin is well-known (Lavialle et al, 1982;Chandani & Balasubramanian, 1986;Bazzo et al, 1988). At micromolar peptide concentrations, melittin is unfolded to a conformation similar to a random coil.…”

Section: Hfip-induced Helix Formation In Melittinmentioning

confidence: 99%

Cooperative α‐helix formation of β‐lactoglobulin and melittin induced by hexafluoroisopropanol

Hirota

Mizuno

Goto³

1997

Protein Science

238

224

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Alcohols denature the native state of proteins, and also stabilize the a-helical conformation in unfolded proteins and peptides. Among various alcohols, trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP) are often used because of their high potential to induce such effects. However, the reason why TFE and HFIP are more effective than other alcohols is unknown. Using CD, we studied the effects of TFE and HFIP as well as reference alcohols, i.e., methanol, ethanol, and isopropanol, on the conformation of bovine P-lactoglobulin and the bee venom melittin at pH 2. Upon addition of alcohols, P-lactoglobulin exhibited a transformation from the native state, consisting of P-sheets, to the a-helical state, whereas melittin folded from the unfolded state to the a-helical state. In both cases, the order of effectiveness of alcohols was shown to be: HFIP > TFE > isopropanol > ethanol > methanol. The alcohol-induced transitions were analyzed assuming a two-state mechanism to obtain the rn value, a measure of the dependence of the free energy change on alcohol concentration. Comparison of the rn values indicates that the high potential of TFE can be explained by the additive contribution of constituent groups, i.e., F atoms and alkyl group. On the other hand, the high potential of HFIP is more than that expected from the additive effects, suggesting that the cooperative formation of micelle-like clusters of HFIP is important.

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Section: Hfip-induced Helix Formation In Melittinmentioning

confidence: 99%

Cooperative α‐helix formation of β‐lactoglobulin and melittin induced by hexafluoroisopropanol

Hirota

Mizuno

Goto³

1997

Protein Science

238

224

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“…Amide I band 1651cm -1 is mainly due to C=O stretching vibration coupled to contribution from the CN stretch, CCN deformation and in-plane bending modes [13]. The amide II band exhibited at a wave number of 1527 cm -1 is a resulted from an out of phase combination of a CN stretch and in-plane NH deformation modes of peptide group [13] [14]. The amide III were observed at wave number 1234 cm -1 , indicated the disorder in the gelatin molecules and were more likely associated with the loss of triple helix state [15] [16].…”

Section: Synthesis Of Mesoporous Silica-aluminamentioning

confidence: 99%

Extraction of gelatin from catfish bone using NaOH and its utilization as a template on mesoporous silica alumina

Nuryanto

Trisunaryanti

Falah

et al. 2018

IOP Conf. Ser.: Mater. Sci. Eng.

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Gelatin extraction from catfish bone using NaOH and its utilization as a template on a synthesis of mesoporous silica-alumina had been investigated. The extraction was prepared by immersing 25 g catfish bone in 125 mL of NaOH in concentration of 0.0; 0.05; 0.10; 0.15 and 0.20 M for 24 h, then washing with demineralized water until pH 7, followed by immersed the bone into 125 mL of 1 M HCl for 1 h, then washed using demineralized water into pH 5. To produce gelatin the bone was refluxed with 100 mL demineralized water at 70C for 5 h then evaporated at 50C. The dry gelatin was characterized using FTIR and electrophoresis (SDS-PAGE). The best performance of gelatin was produced by NaOH 0.10 M. The gelatin consists of amide A, B, I, II, III and molecular weight of 25-200kDa. Silica and Alumina material prepared from Lapindo mud extraction. Dry Lapindo mud crushed and filtered until pass 100 mesh, then reflux using 6 M HCl (1:4 w/V) at 90C for 5h then filtered. The filtrate was consisting alumina solution adding with 6 M NaOH (2/3 V/V) them filtered. The filtrate then injected by CO2 gas for 30 minutes and filtered, the residue was calcined at 500C for 5h. The residual of Lapindo mud dried and refluxed with 6 M NaOH (1:4 w/v) at 90 C. After 5h filtered and the filtrate added by HCl to pH 8 and filtered, the residual then dried. The Si and Al were then analyzed by XRF and consist of silica and alumina for 99.1 and 87.73%, respectively. Silicaalumina was prepared using silica and alumina extracted from Lapindo mud. 6 g of SiO2 and 2 g of NaOH was immersed in 62 mL of demineralized water then added with alumina solution (0.204 g alumina in 30 mL demineralized water). The gelatin solution (5 g gelatin in 70 mL demineralized water) was dropped into the silica-alumina while stirring at 50C for 4 h and aging for 24 h. The synthesized silica alumina was analysed using FTIR and surface area analyser. The FT-IR spectra indicated the TO4 (T=Si, Al) vibration at wave number of 1049.28 and 1103.23 cm -1 . The synthesized silica-alumina showed mesoporous characters with a pore diameter of 41.18 nm and surface area of 32.76 m 2 /g

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“…bending modes. [30,31] The absorption peak at amide I was characteristic for the coil structure of gelatin. [32] Compared with other gelatins, the amide I peak of A1 showed the higher amplitudes and wide peak, which was probably caused by more complete triple helix structure than other LMW gelatin.…”

Section: Ft-ir Spectra Of Gelatinmentioning

confidence: 99%

Molecular structural properties of extracted gelatin from Yak skin as analysed based on molecular weight

Wei

et al. 2017

International Journal of Food Properties

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This paper dealt with the physicochemical, functional and antioxidative properties of Yak skin gelatins with various molecular weights. The gelatin was extracted by alkaline process, and different molecular weight gelatin was achieved by ultrafiltration with different molecular weight cut membrane. The SDS-PAGE showed the molecular weight of the yak skin gelatin. The UV-Vis absorption turned out that the high molecular weight (HMW) of yak skin gelatin had a higher maximum absorption peaks. The FT-IR indicated the change of gelatin structures with the change of the molecular weight. No matter the HMW or the low molecular weight (LMW), the Yak skin gelatin had a high denaturation temperature (T d ), and it was higher than most of the other mammals and marine biological gelatin. The HMW gelatin had higher imino acids contents and lower oxidation resistance, foamability and emulsibility compared to the LMW gelatin. These findings showed that a certain molecular weight range of Yak skin gelatin has great potential for application as an alternative to commercial gelatin due to its good antioxidative, foamability emulsibility and thermotolerance.ARTICLE HISTORY

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Infrared spectroscopic study of the secondary structure of melittin in water, 2-chloroethanol, and phospholipid bilayer dispersions

Cited by 89 publications

References 38 publications

Cooperative α‐helix formation of β‐lactoglobulin and melittin induced by hexafluoroisopropanol

Cooperative α‐helix formation of β‐lactoglobulin and melittin induced by hexafluoroisopropanol

Extraction of gelatin from catfish bone using NaOH and its utilization as a template on mesoporous silica alumina

Molecular structural properties of extracted gelatin from Yak skin as analysed based on molecular weight

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