Protein — FTIR absorption peaks and assignments
These are the characteristic FTIR wavenumbers where Protein 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 320,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
Protein 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
| Wavenumber (cm⁻¹) | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| 1650 | 28 | 27 | 1.0 |
| 1540 | 18 | 16 | 1.0 |
| 1640 | 14 | 12 | 1.0 |
| 1550 | 12 | 10 | 1.0 |
| 1655 | 11 | 11 | 1.0 |
| 1654 | 11 | 11 | 1.0 |
| 1600 | 11 | 10 | 1.0 |
| 1630 | 9 | 9 | 1.0 |
| 1645 | 8 | 8 | 1.0 |
| 1636 | 8 | 8 | 1.0 |
| 1660 | 8 | 8 | 1.0 |
| 1652 | 7 | 7 | 1.0 |
| 1700 | 7 | 7 | 1.0 |
| 1240 | 6 | 6 | 1.0 |
| 1450 | 6 | 6 | 1.0 |
| 1690 | 6 | 5 | 1.0 |
| 1545 | 6 | 5 | 1.0 |
| 3300 | 6 | 4 | 1.0 |
| 1560 | 5 | 5 | 1.0 |
| 1340 | 5 | 5 | 1.0 |
| 1635 | 5 | 5 | 1.0 |
| 1648 | 5 | 5 | 1.0 |
| 970 | 5 | 5 | 1.0 |
| 1637 | 5 | 5 | 1.0 |
| 1338 | 5 | 5 | 1.0 |
| 1400 | 5 | 5 | 1.0 |
| 1656 | 5 | 4 | 1.0 |
| 1657 | 5 | 3 | 1.0 |
| 1649 | 4 | 4 | 1.0 |
| 1639 | 4 | 4 | 1.0 |
Showing the 30 best-supported peaks of 378 total for Protein.
Possible materials
Spectrum logic
A functional-group assignment becomes more confident 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
-
1238 cm⁻¹ confidence 1.0
“The intensity of the cm-1 bands in the 1238-1244 region also decreased in the purified samples, which may be due to the elimination of a small fraction of protein.”
Characterization of polysaccharides from <i>Eremurus hissaricus</i> roots by FTIR spectroscopy DOI: 10.21285/2227-2925-2021-11-2-281-289 -
1637 cm⁻¹ confidence 1.0
“cm-1 The FTIR band at 1637 corresponds to Amide I of collagen [25] that exists in the raw HAP of bovine bone powder and is completely removed in calcined HAP samples.”
XRD and FTIR study of A&B type carbonated hydroxyapatite extracted from bovine bone DOI: 10.1063/1.5089399 -
1648 cm⁻¹ confidence 1.0
“S U cm-1: Region 1700-1000 N cm-1 The vibration 1648 is assigned to C=O stretching of amide I in proteins (mainly - A”
Fourier transform infrared microspectroscopy detects biochemical changes during C. elegans lifespan DOI: 10.1016/j.vibspec.2019.04.005 -
3283 cm⁻¹ confidence 1.0
“The 3 ʋ̵NH last band of the peak level 3283 represents extending peptide Control Abbreviation Vibrational peak assignments (ANHCOA) bonds in proteins [50] and the stretching vibrations of 3(PO43(cid:3))domain PAO PAOasymmetricstretchinginth”
Application of infrared spectroscopy in the identification of Ewing sarcoma: A preliminary report DOI: 10.1016/j.infrared.2017.05.006 -
1030 cm⁻¹ confidence 1.0
“ordered apatite, but a peak at 1030 is indicative of the The collagen in the cornea plays an important role in stoichiometrically ordered apatite [7].”
Chen 等 - 2006 - Corneal calcification chemical composition of cal DOI: 10.1007/s00417-005-1191-0 -
1678 cm⁻¹ confidence 1.0
“Strong vibrational coupling signatures observed in our cm-1 In this study, we have applied a selective isotope-labeling stratdata between the carbonyl stretches and the peak at 1678 egy to isolate the vibrational signals of the protein-boun”
Ground-state heterogeneity and vibrational energy redistribution in bacterial phytochrome observed with femtosecond 2D IR spectroscopy DOI: 10.1063/5.0135268 -
1691 cm⁻¹ confidence 1.0
“(1656cm(cid:2)1), a-helix b-sheet and Krimm [20] observed that The thyroid spectra, in addition to evident strong protein peaks 1691cm(cid:2)1) (1647cm(cid:2)1) (1626, 1679, and unordered secondary cm(cid:2)1 1659cm(cid:2)1, at 1547 and als”
Das 等 - 2008 - FTIR of touch imprint cytology A novel tissue dia DOI: 10.1016/j.jphotobiol.2008.05.012 -
1265 cm⁻¹ confidence 1.0
“Moreover, three characteristic cm1, cm1 cm1 peaks originating from protein vibrations were noticed at 1265 1525 and 1654 (amide III, amide II, amide I, respectively).”
Effect of High Blood Cortisol Concentration on the Spectroscopically Determined Secondary Structure of Proteins and Lipid Balance on the Example of Elite Women Volleyball Players DOI: 10.21203/rs.3.rs-228476/v1
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