scholarly journals DEVELOPMENT OF EYE COLORS IN DROSOPHILA: SOME PROPERTIES OF THE HORMONES CONCERNED

1938 ◽  
Vol 22 (2) ◽  
pp. 239-253 ◽  
Author(s):  
Edward L. Tatum ◽  
G. W. Beadle
Keyword(s):  
Molecular Weight ◽  
Molecular Oxygen ◽  
Hormone Concentration ◽  
Wild Type ◽  
Simple Method ◽  
Intracellular Enzyme ◽  
Eye Color ◽  
Stable Chemical ◽  
Amphoteric Compound

The substance inducing the production of pigment in the eyes of vermilion brown mutants of Drosophila melanogaster has been shown to be a relatively stable chemical entity possessing true hormone-like activity. A simple method for obtaining hormone solutions has been developed involving extraction of dried wild type Drosophila pupae with ethyl alcohol and water. A logarithmic proportionality has been found to exist between the amount of hormone and the induced eye color. This relationship provides a simple method for the quantitative determination of hormone concentration in given extracts. Larvae and pupae of D. melanogaster contain an intracellular enzyme which inactivates the hormone in the presence of molecular oxygen. The hormone is not oxidized under ordinary conditions with either molecular oxygen or hydrogen peroxide. The hormone has been found to be an amphoteric compound with both acidic and basic groups and with a molecular weight between 400 and 600. The solubility and precipitation reactions of the hormone suggest its amino acid-like nature. However, the instability to heat, acid, and alkali, and its rather restricted occurrence indicate a rather complex specific structure.

scholarly journals Facile Molecular Weight Determination of Polymer Brushes Grafted from One-Dimensional Diffraction Grating by SI-ATRP Using Reflective Laser System

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4270
Author(s):  
Jem-Kun Chen ◽  
Feng-Ping Lin ◽  
Chi-Jung Chang ◽  
Chien-Hsing Lu ◽  
Chih-Feng Huang
Keyword(s):  
Molecular Weight ◽  
Polymer Brushes ◽  
Diffraction Effect ◽  
Molecular Weight Determination ◽  
Diffraction Intensity ◽  
Simple Method ◽  
Grafting Polymerization ◽  
One Dimensional ◽  
Wide Range

Gelatin was immobilized selectively on the amide groups-modified bottom of a trench array of a photoresist template with 2 μm resolution by the ethyl(dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide reaction. The gelatin-immobilized line array was brominated to generate a macroinitiator for atom transfer radical polymerization. Poly(methacrylic acid) (PMAA) brushes were grafted from the macroinitiator layer as line arrays of one-dimensional diffraction gratings (DGs) for various grafting polymerization times. A laser beam system was employed to analyze the optical feature with a characteristic diffraction effect of the PMAA DGs at a 45° incident angle along the transverse magnetic and transverse electric polarization. The growth of the PMAA brush lines increased both their heights and widths, leading to a change in the reflective diffraction intensity. The PMAA brushes under various grafting polymerization times were cleaved from the substrate by digestion of gelatin with trypsin, and their molecular weights were obtained by gel permeation chromatography. The change degree of the diffraction intensity varied linearly with the molecular weight of the PMAA brushes over a wide range, from 135 to 1475 kDa, with high correlation coefficients. Molecular weight determination of polymer brushes using the reflective diffraction intensity provides a simple method to monitor their growth in real time without polymer brush cleavage.

scholarly journals Quaternary Structure and Hetero-Oligomerization of Recombinant Human Small Heat Shock Protein HspB7 (cvHsp)

2021 ◽  
Vol 22 (15) ◽  
pp. 7777
Author(s):  
Lydia K. Muranova ◽  
Vladislav M. Shatov ◽  
Andrey V. Slushchev ◽  
Nikolai B. Gusev
Keyword(s):  
Molecular Weight ◽  
Heat Shock ◽  
Quaternary Structure ◽  
Small Heat Shock Protein ◽  
Apparent Molecular Weight ◽  
Size Exclusion ◽  
Wild Type ◽  
Simple Method ◽  
Exclusion Chromatography ◽  
Shock Proteins

In this study, a reliable and simple method of untagged recombinant human HspB7 preparation was developed. Recombinant HspB7 is presented in two oligomeric forms with an apparent molecular weight of 36 kDa (probably dimers) and oligomers with an apparent molecular weight of more than 600 kDa. By using hydrophobic and size-exclusion chromatography, we succeeded in preparation of HspB7 dimers. Mild oxidation promoted the formation of large oligomers, whereas the modification of Cys 126 by iodoacetamide prevented it. The deletion of the first 13 residues or deletion of the polySer motif (residues 17–29) also prevented the formation of large oligomers of HspB7. Cys-mutants of HspB6 and HspB8 containing a single-Cys residue in the central part of the β7 strand in a position homologous to that of Cys137 in HspB1 can be crosslinked to the wild-type HspB7 through a disulfide bond. Immobilized on monoclonal antibodies, the wild-type HspB6 interacted with the wild-type HspB7. We suppose that formation of heterodimers of HspB7 with HspB6 and HspB8 may be important for the functional activity of these small heat shock proteins.

Simplified Determination of Fibrinogen Subfractions by Glycine

1979 ◽  
Author(s):  
S. Sasaki ◽  
K. Kito
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Human Plasma ◽  
Gel Electrophoresis ◽  
Biological Properties ◽  
Strength Analysis ◽  
Simple Method ◽  
Molecular Fraction ◽  
The Difference

Although it has been suggested by some investigators that human plasma fibrinogen is composed of two or more subfractions, no simple method of determining these fractions individually has been available for clinical use. We found that precipitation by glycine at certain ionic strength was suitable for this purpose. One volume of human plasma was added to 10 volume of 2.3 M glycine solution of varying ionic strength. Analysis of the precipitates obtained at various Ionic strength by means of SDS-gel electrophoresis gave the following results: The precipitate obtained at ionic strength 0.2 gave single band. Its molecular weight was 360,000, clottability 85%. The supernatant was devoid of this fraction. The precipitate obtained at ionic strength 1.4 gave two banda corresponding to molecular weight of 360,000 and 325,00O respectively. The clottability of the precipitate was 85%. The supernatant contained no significant amount of clottable protein. It is therefore possible to determine the concentrations of high molecular fraction of fibrinogen and of total fibrinogen in plasma using the precipitate at ionic strength 0.2 and the precipitate at ionic strength 1.4 respectively. The difference of the two values gives the concentration of low molecular fraction of fibrinogen. Biological properties of the two fractions were also studied.

Development of a simple method for the determination of single nucleotide polymorphisms

2010 ◽  
Vol 34 (8) ◽  
pp. S75-S75
Author(s):  
Weifeng Zhu ◽  
Zhuoqi Liu ◽  
Daya Luo ◽  
Xinyao Wu ◽  
Fusheng Wan
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Nucleotide Polymorphisms ◽  
Simple Method ◽  
Single Nucleotide
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