Protein beta turn — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where Protein beta turn tends to absorb, compiled from published literature and ranked by supporting evidence. Each assignment is traceable to a source (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
Protein beta turn is usually assigned by looking for a recurring cluster of characteristic peaks rather than one exact textbook number. The table below shows where the literature most often places this group in FTIR, ranked by accumulated evidence.
Characteristic FTIR peaks for Protein beta turn
| Wavenumber (cm⁻¹) | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 1660 | 5 | 5 | 1.0 |
| 1630 | 3 | 3 | 1.0 |
| 1680 | 3 | 3 | 1.0 |
| 1688 | 3 | 3 | 1.0 |
| 1690 | 3 | 3 | 1.0 |
| 1650 | 2 | 2 | 1.0 |
| 1670 | 2 | 2 | 1.0 |
| 1678 | 2 | 2 | 1.0 |
| 1640 | 2 | 2 | 1.0 |
| 1666 | 2 | 2 | 0.9 |
| 1656 | 2 | 1 | 1.0 |
| 1317 | 1 | 1 | 1.0 |
| 1702 | 1 | 1 | 1.0 |
| 1629 | 1 | 1 | 1.0 |
| 1267 | 1 | 1 | 1.0 |
| 1620 | 1 | 1 | 1.0 |
| 1689 | 1 | 1 | 1.0 |
| 1652 | 1 | 1 | 1.0 |
| 650 | 1 | 1 | 1.0 |
| 1080 | 1 | 1 | 1.0 |
| 1686 | 1 | 1 | 1.0 |
| 1683 | 1 | 1 | 1.0 |
| 1653 | 1 | 1 | 1.0 |
| 1694 | 1 | 1 | 1.0 |
| 1671 | 1 | 1 | 1.0 |
| 1665 | 1 | 1 | 1.0 |
| 2006 | 1 | 1 | 1.0 |
| 1542 | 1 | 1 | 1.0 |
| 1642 | 1 | 1 | 1.0 |
| 1600 | 1 | 1 | 1.0 |
Showing the 30 best-supported peaks of 38 total for Protein beta turn.
Spectrum logic
A functional-group assignment becomes more reliable when several expected bands appear together. Use this page to find the strongest-supported peaks, then confirm that the same sample exhibits a coherent pattern rather than a single isolated hit.
Real-world usage
These pages are useful for unknown material analysis, peak explanation in reports, polymer troubleshooting, and verifying whether a candidate material family is chemically plausible.
Common mistakes
- Using one functional-group page as a complete material verdict without checking the rest of the spectrum.
- Assuming the strongest band is always the most diagnostic one.
- Forgetting that processing, additives, aging, and mixtures can shift or broaden expected peaks.
Verification advice
Use DSC, GC-MS, or TGA when several material families share similar bands or when mixture effects make the FTIR assignment uncertain.
Literature behind these assignments
-
660 cm⁻¹ confidence 1.0
“wavenumber components of Amide I at about 1,690the 12 low-complexity, highly repetitive blocks, which are mainly 1,660cm-1, β-turns β-sheet assigned to vibrations of unordered and involved in the formation of the crystalline domains, domain”
Biagiotti 等 - 2022 - Electrospun Silk Fibroin Scaffolds for Tissue Rege DOI: 10.3389/fbioe.2022.833157 -
1690 cm⁻¹ confidence 1.0
“Peaks between 1690 and 1665 are generally assigned to β-turn structures.”
Fevzioglu 等 - 2020 - Quantitative approach to study secondary structure DOI: 10.1016/j.ijbiomac.2020.07.299 -
1660 cm⁻¹ confidence 1.0
“The peaks at 1692 1687 (-) cm-1 77 and 100 K are enlarged by 1/0.36 and 1/0.64, respectively, and 1673 can be attributed to the amide I vibrations (+) (-) to normalize the population of D447 photoconverted to S390 of turn structure, and the”
Iwata 等 - 2003 - Light-induced structural changes in the LOV2 domai DOI: 10.1021/bi0345135 -
1676 cm⁻¹ confidence 1.0
“The positive influence of PC2 loadings had three peaks at 1676, 1630 cm-1 assigned to amide I (β-turns and β-sheets), and 1063 cm-1 (mostly might be related to cellulose and hemicellulose) which differentiated the control SR (outstanding) f”
Specific Mycoparasite-Fusarium Graminearum Molecular Signatures in Germinating Seeds Disabled Fusarium Head Blight Pathogen’s Infection DOI: 10.3390/ijms22052461 -
1693 cm⁻¹ confidence 1.0
“bands at 1632, 1641, 1673, and 1680 cm-1 are assigned to β-sheet secondary structures, while those bands at 1632, 1641, 1673, and 1680 cm-1 are assigned to β-sheet secondary structures, while those bands at 1632, 1641, 1673, and 1680 cm-1 a”
Sadat 和 Joye - 2020 - Peak Fitting Applied to Fourier Transform Infrared DOI: 10.3390/app10175918 -
1678 cm⁻¹ confidence 1.0
“The 1678 absorption in the FTIR spectrum of bone is associated with the β-turn conformation of collagen.”
Assessment of collagen quality associated with non-enzymatic cross-links in human bone using Fourier-transform infrared imaging DOI: 10.1016/j.bone.2017.01.015. -
1664 cm⁻¹ confidence 1.0
“cm-1), α-helix There was a significant difference in the band (~1664 which was significantly cm-1) β-turn higher in bulbar patients, while the and loops band (~1680 was significantly more pronounced in samples from spinal ALS patients.”
Synchrotron-Based Fourier-Transform Infrared Micro- Spectroscopy of Cerebrospinal Fluid from Amyotrophic Lateral Sclerosis Patients Reveals a Unique Biomolecular Profile DOI: 10.3390/cells12111451 -
1650 cm⁻¹ confidence 1.0
“The inverted peak at 1618 cm-1 attests the higher content of β-strands cm-1, β-turn a decrease in intensity is observed at 1680 probably due to content which is for hard silk, while the shoulder at 1650 cm-1 is a sign of the high content of”
Historical Silk: A Novel Method to Evaluate Degumming with Non-Invasive Infrared Spectroscopy and Spectral Deconvolution DOI: 10.3390/ma16051819
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