Source 1primary paper1995Protein Science
Toolkit/Edelhoch method
Edelhoch method
Taxonomy: Technique Branch / Method. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
The studies reported here suggest that the Edelhoch method is the best method for measuring epsilon for a protein.
Usefulness & Problems
Why this is useful
The Edelhoch method is presented as an experimental method for measuring a protein's molar absorption coefficient, epsilon. The abstract specifically recommends it for direct measurement rather than relying only on prediction.; measuring protein molar absorption coefficient (epsilon)
Source:
The Edelhoch method is presented as an experimental method for measuring a protein's molar absorption coefficient, epsilon. The abstract specifically recommends it for direct measurement rather than relying only on prediction.
Source:
measuring protein molar absorption coefficient (epsilon)
Problem solved
It addresses how to obtain protein epsilon values for concentration determination and related spectroscopic use cases.; provides an experimental method to determine protein epsilon
Source:
It addresses how to obtain protein epsilon values for concentration determination and related spectroscopic use cases.
Source:
provides an experimental method to determine protein epsilon
Problem links
provides an experimental method to determine protein epsilon
LiteratureIt addresses how to obtain protein epsilon values for concentration determination and related spectroscopic use cases.
Source:
It addresses how to obtain protein epsilon values for concentration determination and related spectroscopic use cases.
Taxonomy & Function
Primary hierarchy
Technique Branch
Method: A concrete measurement method used to characterize an engineered system.
Mechanisms
uv absorbance measurement at 280 nmTechniques
Functional AssayTarget processes
No target processes tagged yet.
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationoperating role: sensor
The abstract supports that this is an absorbance-based protein measurement method, but does not provide the full protocol or instrumentation details.; requires absorbance-based measurement of protein epsilon
The abstract does not show that it removes all uncertainty for every protein class, and it does not provide a full workflow for proteins lacking key chromophores.; the abstract does not provide protocol details
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
Protein absorbance at 280 nm depends on the content of Trp, Tyr, and cystine.
The absorbance of a protein at 280 nm depends on the content of Trp, Tyr, and cystine (disulfide bonds).
Although prediction is possible, the best approach is to measure rather than predict protein epsilon.
However, the Edelhoch method is convenient and accurate, and the best approach is to measure rather than predict epsilon.
The Edelhoch method is the best method for measuring the molar absorption coefficient of a protein.
The studies reported here suggest that the Edelhoch method is the best method for measuring epsilon for a protein.
The epsilon at 280 nm of a folded protein in water can be predicted as epsilon(280) = (#Trp)(5500) + (#Tyr)(1490) + (#cystine)(125).
Based on a sample of 116 measured epsilon values for 80 proteins, the epsilon at 280 nm of a folded protein in water, epsilon (280), can best be predicted with this equation: epsilon (280) (M-1 cm-1) = (#Trp)(5,500) + (#Tyr)(1,490) + (#cystine)(125)
cystine coefficient 125 M-1 cm-1measured epsilon values 116 valuesproteins sampled 80 proteinsTrp coefficient 5500 M-1 cm-1Tyr coefficient 1490 M-1 cm-1
The epsilon(280) prediction values are quite reliable for proteins containing Trp residues and less reliable for proteins that do not.
These epsilon (280) values are quite reliable for proteins containing Trp residues, and less reliable for proteins that do not.
Approval Evidence
1 source2 linked approval claimsfirst-pass slug edelhoch-method
The studies reported here suggest that the Edelhoch method is the best method for measuring epsilon for a protein.
Source:
method preferencesupports
Although prediction is possible, the best approach is to measure rather than predict protein epsilon.
However, the Edelhoch method is convenient and accurate, and the best approach is to measure rather than predict epsilon.
Source:
method recommendationsupports
The Edelhoch method is the best method for measuring the molar absorption coefficient of a protein.
The studies reported here suggest that the Edelhoch method is the best method for measuring epsilon for a protein.
Source:
Comparisons
Source-stated alternatives
The abstract contrasts direct measurement by the Edelhoch method with prediction from amino acid composition and with concentration estimates based on dry weight, nitrogen, or amino acid analysis.
Source:
The abstract contrasts direct measurement by the Edelhoch method with prediction from amino acid composition and with concentration estimates based on dry weight, nitrogen, or amino acid analysis.
Source-backed strengths
described as convenient and accurate; described as the best method for measuring epsilon for a protein
Source:
described as convenient and accurate
Source:
described as the best method for measuring epsilon for a protein
Compared with Langendorff perfused heart electrical recordings
Edelhoch method and Langendorff perfused heart electrical recordings address a similar problem space.
Shared frame: same top-level item type
Strengths here: looks easier to implement in practice.
Compared with native green gel system
Edelhoch method and native green gel system address a similar problem space.
Shared frame: same top-level item type
Strengths here: looks easier to implement in practice.
Edelhoch method and sub-picosecond pump-probe analysis of bacteriorhodopsin pigments address a similar problem space.
Shared frame: same top-level item type
Strengths here: looks easier to implement in practice.
Ranked Citations
- 1.