^a pred. MW was calculated based on protein sequence as retrieved from the ExPASy molecular biology WWW server of the Swiss Institute of Bioinformatics (SIB) http://expasy.hcuge.ch/  (except of Aprotinin)
^b    SD represents one standard deviation calculated as  S.D. =  SQRT{ [sum(Yi-M)^2]/(n-1)}  ,   where
    M     is arithmetic mean caluclated as M = sum(Yi )/n   (given in column "Average Experimental MW")
    Yi     is a result of the "ith" measurement , i.e. MW determined in the "ith" run    
    n      is a number of runs
^c    % error is calculated as an average from the absolute values of {100x[(Experimental MW-pred. MW)/pred. MW]}
^d   these dimers are unstable under chromatographic condition used, i.e. buffer with 1 mM EDTA.
^e   colored protein: absorbs at the wavelength of the laser beam (633 nm).  Thus the amount of scattered light is smaller and leads to underestimated Mw as the instrument is not capable of correcting for the absorbed light.
^f   analyzed on Superdex 75 column in 20 mM HEPES, 600 mM KCl, 1 mM EDTA , 1 mM DTT, pH=8.0
 

Molecular Weight Determined from  "two detector" analysis
 

Protein	Oligomeric state	predicted MW (kDa)	number of runs	Average Experimental MW (kDa)	SDa) (kDa)	Average differenceb) (%)	comments
Alcohol   Dehydrogenase	tetramer	147.5	4	145.8	1.5	1.2
BSA (monomer)	monomer	66.4	5	67.1	0.9	1.2
BSA (dimer)	dimer	132.9	5	140.6	2.8	5.8
Carbonic     Anhydrase	monomer	29.0	4	29.8	1.0	3.8
Cytochrome C	monomer	12.3	5	11.9	0.2	2.9*	colored*
Apo-ferritin	24*monomer	475.9	2	469.8	0.3	1.3
Alfa-Lactalbumin	monomer	14.2	2	15.1	0.03	6.8
Aldolase (rabbit)	tetramer	156.8	1	150.6		2.2
Beta-lactglobulin	monomer +dimer	18.3	2	21.5	0.5	17.5	known to dimerize at low pH
Enolase (rabbit)	dimer +monomer	93.7	4	86.9	1.5	7.2**	needs Mg2+ for dimer stability
Enolase (yeast)	dimer +monomer	93.3	1	80.1		14.2**	needs Mg2+ for dimer stability
Glutamate    Dehydrogenase	hexamer	333.4	6	461.6	44.2	38.5	"tailing" polydisperse peak
Myoglobin	monomer	17.0	3	14.2	1.6	16.2*	colored*
Transferrin	monomer	75.2	2	78.0	0.3	3.8
Trypsin Inhibitor	monomer	20.0	1	21.0		5.0
Ovalbumin	monomer	42.8	10	43.6	0.5	1.9

Buffer used:  20 mM HEPES, 100 mM KCl, 1 mM EDTA pH=8.0 @ RT
 
^a)   SD represents one standard deviation calculated as S.D. =  SQRT{ [sum(Yi-M)^2]/(n-1)}, where
M     is arithmetic mean caluclated as M = sum(Yi )/n   (given in column "Average Experimental MW")
Yi     is a result of the "ith" measurement , i.e. MW determined in the "ith" run    
n      is a number of runs
^b)    Average difference (%) is calculated as absolute value of {100*[(Average Experimental MW-predicted MW)/predicted MW]}
 
* colored proteins absorb at the wavelength of the laser beam (633 nm).  Thus the amount of scattered light is smaller and leads to underestimated Mw as the instrument is not capable of correcting for the absorbed light.
** these dimers are unstable under chromatographic condition used, i.e. buffer with 1 mM EDTA.
 

Molecular Weight Determined from ASTRA analysis
 

Protein	Oligomeric state	Predicted MW (kDa)	Number of runs	Average Experimental MW (kDa)	SD (kDa)	Average difference (%)	Comments
Alcohol   Dehydrogenase	tetramer	147.5	4	144.0	0.9	2.4
BSA (monomer)	monomer	66.4	5	67.1	1.0	1.2
BSA (dimer)	dimer	132.9	5	137.1	3.9	3.2
Carbonic     Anhydrase	monomer	29.0	4	29.2	0.2	0.8
Cytochrome C	monomer	12.3	5	12.0	0.6	2.4*	colored*
Apo-ferritin	24*monomer	475.9	2	470.4	2.6	1.2
Alfa-Lactalbumin	monomer	14.2	2	14.3	0.01	0.9
Aldolase (rabbit)	tetramer	156.8	1	155.1		1.1
Beta-lactglobulin	monomer +dimer	18.3	2	20.1	0.3	9.7	known to dimerize at low pH
Enolase (rabbit)	dimer +monomer	93.7	4	86.4	1.9	7.8**	needs Mg2+ for dimer stability
Enolase (yeast)	dimer +monomer	93.3	1	79.5		14.9**	needs Mg2+ for dimer stability
Glutamate    Dehydrogenase	hexamer	333.4	6	486.5	48.7	45.9	"tailing" polydisperse peak
Myoglobin	monomer	17.0	3	14.2	0.9	16.3*	colored*
Transferrin	monomer	75.2	2	76.9	1.0	2.3
Trypsin Inhibitor	monomer	20.0	1	20.5		2.3
Ovalbumin	monomer	42.8	10	42.5	0.7	1.4

Buffer used:  20 mM HEPES, 100 mM KCl, 1 mM EDTA pH=8.0 @ RT

^a)    SD represents one standard deviation calculated as  S.D. =  SQRT{ [sum(Yi-M)^2]/(n-1)}  ,   where
M     is arithmetic mean caluclated as M = sum(Yi )/n   (given in column "Average Experimental MW")
Yi     is a result of the "ith" measurement , i.e. MW determined in the "ith" run    
n      is a number of runs

^b)    Average difference (%) is calculated as absolute value of {100*[(Average Experimental MW-predicted MW)/predicted MW]}

* colored proteins absorb at the wavelength of the laser beam (633 nm) and the instrument  is not capable of correcting for the absorbed light.  Thus the amount of scattered light is smaller and leads to underestimated Mw.
** these dimers are unstable under chromatographic condition used, i.e. buffer with 1 mM EDTA.

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