Protein alpha helix — FTIR-absorptions-toppe og tildelinger

Hurtigt svar

Protein alpha helix tildeles normalt ved at lede efter en tilbagevendende klynge af karakteristiske toppe frem for et præcist lærebogsnummer. Tabellen nedenfor viser, hvor litteraturen oftest placerer denne gruppe i FTIR, rangeret efter akkumuleret evidens.

Karakteristiske FTIR-toppe for Protein alpha helix

Viser de 30 bedst understøttede toppe ud af 97 i alt for Protein alpha helix.

Spektrumlogik

En funktionel gruppetildeling bliver mere sikker, når flere forventede bånd optræder sammen. Brug denne side til at finde de bedst understøttede peaks, og bekræft derefter, at den samme prøve udviser et sammenhængende mønster snarere end et enkelt isoleret hit.

Anvendelse i virkeligheden

Disse sider er nyttige til analyse af ukendte materialer, topforklaring i rapporter, polymerfejlfinding og verifikation af, om en kandidatmaterialefamilie er kemisk plausibel.

Almindelige fejl

• Brug af én funktionel-gruppe-side som en komplet materialebedømmelse uden at kontrollere resten af spektret.
• Antager, at det stærkeste bånd altid er det mest diagnostiske.
• At glemme, at forarbejdning, tilsætningsstoffer, ældning og blandinger kan flytte eller udvide forventede toppe.

Verifikationsrådgivning

Brug DSC, GC-MS eller TGA, når flere materialefamilier deler lignende bånd, eller når blandings-effekter gør FTIR-tildelingen usikker.

Litteratur bag disse tildelinger

• 1695 cm⁻¹ tillid 1,0

  “The broad bands in the raw spectrum at 1695 ad cm-1 (α-helix β-sheet 1637 were associated with amide I and cm-1 structures of proteins) while the signal at 1520 corre-”

  Baldauf 等 - 2007 - Effect of selective growth media on the differenti DOI: 10.1016/j.mimet.2006.06.012
• 1648 cm⁻¹ tillid 1,0

  “cm-1 The vibration 1648 is assigned to C=O stretching of amide I in proteins (mainly - A helix components of proteins) [24, 31].”

  Fourier transform infrared microspectroscopy detects biochemical changes during C. elegans lifespan DOI: 10.1016/j.vibspec.2019.04.005
• 1645 cm⁻¹ tillid 1,0

  “1538 0.066 1537 0.064 Amide II due to N-H bending of proteins [15,17] Amide I due to C=O stretching of α-helix proteins 1645 0.07 1641 0.071 [17] 2924 0.028 2926 0.02 asymmetric stretching symmetric CH2: lipids [18] 2965 0.027 2962 0.019 as”

  A Preliminary Study of FTIR Spectroscopy as a Potential Non-Invasive Screening Tool for Pediatric Precursor B Lymphoblastic Leukemia DOI: 10.3390/molecules
• 1650 cm⁻¹ tillid 1,0

  “The amide I peak (1650 cm-1) is stronger in normal tissues due to the high amount of protein with an α-helical secondary structure.”

  Ghassemi 等 - 2021 - Diagnosis of normal and malignant human gastric ti DOI: 10.1016/j.molstruc.2020.129493
• 1283 cm⁻¹ tillid 1,0

  “At lower wavenumber, the bands at cm-1 α-helices 1283 is assigned to of the amide III absorption band owing to in-phase combination of CH stretching and NH bending vibrations [42].”

  Gupta 等 - 2022 - In vitro cell composition identification of wood d DOI: 10.1098/rsos.201935
• 1550 cm⁻¹ tillid 1,0

  “1550 due to bending vibration of N-H group (60%) α-helix β-sheet and stretching vibration of C-N group (40%).”

  Gene-Transformation-Induced Changes in Chemical Functional Group Features and Molecular Structure Conformation in Alfalfa Plants Co-Expressing Lc-bHLH and C1-MYB Transcriptive Flavanoid Regulatory Genes: Effects of Single-Gene and Two-Gene Insertion DOI: 10.3390/ijms18030664
• 1424 cm⁻¹ tillid 1,0

  “in combination with a visible alteration in the protein 1049.1 and 1158.1 to 1161.5 In Muchmore, cm-1 (α-helix β-sheet) region turned to following pathogenic the peaks at 1423.5, 1375.9, and 1052.5 were cm-1”

  Synchrotron based phase contrast X-ray imaging combined with FTIR spectroscopy reveals structural and biomolecular differences in spikelets play a significant role in resistance to Fusarium in wheat DOI: 10.1186/s12870-014-0357-5
• 1655 cm⁻¹ tillid 1,0

  “Typically, a shoulder at is assigned to β-sheet cm-1 secondary structures of proteins, while the band at 1655 is assigned to α-helix secondary structure [24], thus amide I band of the SC at the latter frequency reflects the”

  Mansour 等 - 2017 - Elucidation of penetration enhancement mechanism o DOI: 10.1016/j.saa.2017.05.026