Molecular weights of the α chains of chicken bone collagen by high-speed sedimentation equilibrium

Biochemistry ◽  
1969 ◽  
Vol 8 (6) ◽  
pp. 2609-2615 ◽  
Author(s):  
Elton P. Katz ◽  
Camille J. Francois ◽  
Melvin J. Glimcher
Keyword(s):  
High Speed ◽  
Bone Collagen ◽  
Sedimentation Equilibrium ◽  
Molecular Weights ◽  
Chicken Bone

scholarly journals Biophysical characterization of Artemia salina (L.) extracellular haemoglobins

1981 ◽  
Vol 193 (1) ◽  
pp. 353-359 ◽  
Author(s):  
E J Wood ◽  
C Barker ◽  
L Moens ◽  
W Jacob ◽  
J Heip ◽  
...  
Keyword(s):  
High Speed ◽  
Artemia Salina ◽  
Low Ph ◽  
Sedimentation Equilibrium ◽  
Guanidinium Chloride ◽  
Electron Microscopic ◽  
Biophysical Characterization ◽  
Molecular Weights ◽  
Dimeric Model

Sedimentation coefficients (s0 20,w) of 11.57 +/- 0.10 S and 11.52 +/- 0.09 S were assigned for Artemia salina (L.) extracellular haemoglobins II and III respectively. These values are not significantly different. The molecular weights, M0w and M0z, of the native haemoglobins as determined by the high-speed sedimentation-equilibrium method were for haemoglobin II 239 400 +/- 7200 and 240 400 +/- 2600 respectively, and for haemoglobin III 216 300 +/- 6500 and 219 300 +/- 4500 respectively. The observed increase of Mapp. with concentration suggested that association was occurring over the concentration range investigated. Exposure of haemoglobin II to either 6 M-guanidinium chloride or to low pH (pH 4) resulted in dissociation to units of approximately half the size of the native protein, with molecular weights approx. 115 000. Electron-microscopic observations indicated a molecular structure composed of two stacked lobed discs. These results strongly support the dimeric model for Artemia haemoglobins proposed by Moens & Kondo [(1978) Eur. J. Biochem. 82, 65-72].

An Experimental Investigation of the Auto-Ignition Properties of Two C5 Esters: Methyl Butanoate and Butyl Methanoate

2007 ◽  
Author(s):  
Stephen M. Walton ◽  
Carlos Perez ◽  
Margaret S. Wooldridge
Keyword(s):  
Low Temperature ◽  
High Speed ◽  
Combustion Engine ◽  
Low Temperature Combustion ◽  
Moderate Pressure ◽  
Molecular Weights ◽  
Auto Ignition ◽  
Methyl Butanoate ◽  
Temperature Combustion ◽  
Time Histories

Ignition studies of two small esters were performed using a rapid compression facility (RCF). The esters (methyl butanoate and butyl methanoate) were chosen to have matching molecular weights, and C:H:O ratios, while varying the lengths of the constituent alkyl chains. The effect of functional group size on ignition delay time was investigated using pressure time-histories and high speed digital imaging. The mixtures studied covered a range of conditions relevant to oxygenated fuels and fuel additives, including bio-derived fuels. Low temperature and moderate pressure conditions were selected for study due to their relevance to advanced low temperature combustion strategies, and internal combustion engine conditions. The results are discussed in terms of the reaction pathways affecting the ignition properties.

Molecular Weights of CTLA-4 and CD80 by Sedimentation Equilibrium Ultracentrifugation

1999 ◽  
Vol 270 (2) ◽  
pp. 286-295 ◽  
Author(s):  
Robert Fairman ◽  
William Fenderson ◽  
Mark E. Hail ◽  
Youling Wu ◽  
Shyh-Yu Shaw
Keyword(s):  
Sedimentation Equilibrium ◽  
Molecular Weights ◽  
Equilibrium Ultracentrifugation

scholarly journals Sedimentation-equilibrium studies on the heterogeneity of two β-lactamases

1970 ◽  
Vol 118 (3) ◽  
pp. 467-474 ◽  
Author(s):  
P. H. Lloyd ◽  
A. R. Peacocke
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficients ◽  
Minor Component ◽  
Theoretical Solution ◽  
Sedimentation Equilibrium ◽  
Equilibrium Studies ◽  
Molecular Weights ◽  
A Minor

Solutions of crystalline β-lactamase I and β-lactamase II, prepared by Kuwabara (1970), were examined in the ultracentrifuge and their sedimentation coefficients, diffusion coefficients, molecular weights and heterogeneity determined. Each sample was shown to consist of a major component comprising at least 97% of the material and a minor component of much higher molecular weight. The molecular weights of the major components were 27800 for β-lactamase I and 35600 for β-lactamase II. Emphasis is placed on a straightforward practical way of analysing the sedimentation-equilibrium results on mixtures of two macromolecular components rather than on a strict theoretical solution. Appendices describe the theory of systems at both chemical and sedimentation equilibrium and the procedure for calculating the combined distribution of two components.

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