A COMPARISON OF PHOSVITINS PREPARED FROM HEN'S SERUM AND FROM HEN'S EGG YOLK

1961 ◽  
Vol 39 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Chi-Ching Mok ◽  
W. G. Martin ◽  
R. H. Common
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Egg Yolk ◽  
Terminal Amino Acid ◽  
Weight Average Molecular Weight ◽  
Sedimentation Constant ◽  
Hen’S Egg ◽  
Zone Electrophoresis ◽  
Terminal Amino ◽  
Tryptophan Content

A phosvitin has been prepared from the serum of estrogenized laying hens and partially characterized on the basis of its contents of N (12.3%), P (10.1%), serine (31.0%), and tryptophan (0.56%). Examination of this serum phosvitin and a yolk phosvitin preparation for N-terminal groups yielded identical chromatographic patterns. Alanine was the major N-terminal amino acid with minor amounts of N-terminal lysine. The sedimentation constant [Formula: see text], weight-average molecular weight 4.2 × 104(Archibald method), and number-average molecular weight 4.0 × 104(calculated from the tryptophan content) of the serum phosvitin were similar to those of the phosvitin prepared from egg yolk by the same preparative technique. The two preparations behaved similarly when subjected to zone electrophoresis on paper.Zone electrophoretic evidence is submitted for the presence of phosvitin in the supernatant from dilution precipitation of crude lipophosphoprotein from laying hen's serum as well as in the precipitate itself.

N-TERMINAL AMINO ACIDS OF THE PROTEINS OF THE FLOATING FRACTION OF EGG YOLK

1958 ◽  
Vol 36 (9) ◽  
pp. 951-952 ◽  
Author(s):  
David B. Smith ◽  
K. J. Turner
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Primary Structure ◽  
Egg Yolk ◽  
Minor Components ◽  
Terminal Amino Acid ◽  
Hen’S Egg ◽  
Terminal Amino

Lysine is the major N-terminal amino acid of both the soluble and insoluble fractions of the floating lipoprotein of hen's egg yolk, which suggests a common primary structure. Several minor components are also present in both fractions.

N-TERMINAL AMINO ACIDS OF THE PROTEINS OF THE FLOATING FRACTION OF EGG YOLK

1958 ◽  
Vol 36 (1) ◽  
pp. 951-952 ◽  
Author(s):  
David B. Smith ◽  
K. J. Turner
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Primary Structure ◽  
Egg Yolk ◽  
Minor Components ◽  
Terminal Amino Acid ◽  
Hen’S Egg ◽  
Terminal Amino

Lysine is the major N-terminal amino acid of both the soluble and insoluble fractions of the floating lipoprotein of hen's egg yolk, which suggests a common primary structure. Several minor components are also present in both fractions.

TERMINAL AMINO ACIDS OF EGG YOLK LIPOPROTEINS

1961 ◽  
Vol 39 (6) ◽  
pp. 1075-1084 ◽  
Author(s):  
J. M. Neelin ◽  
W. H. Cook
Keyword(s):  
Amino Acids ◽  
Average Molecular Weight ◽  
Egg Yolk ◽  
Water Soluble ◽  
Terminal Amino Acid ◽  
Physical Measurements ◽  
Terminal Amino ◽  
Polypeptide Chains ◽  
Protein Moiety ◽  
Egg Yolk Lipoproteins

The N-terminal amino acids of the two lipovitellins and lipovitellenin of egg yolk have been determined. α-Lipovitellin and β-lipovitellin were separated by chromatography on hydroxyapatite but the lipovitellenin in the low-density fraction did not yield stable and reproducible chromatographic components. The major N-terminal amino acids recovered as dinitrophenyl derivatives from all three fractions were arginine and lysine. Further purification removed several minor components, but tyrosine and serine remained in vitellin, and alanine and serine in vitellenin. The principal C-terminal amino acid of vitellenin was glutamic acid. Arginine appeared to be the chief N-terminal residue but difficulty in purifying the water-soluble dinitrophenyl-amino acids led to highly variable yields; thus the total calculated amounts of terminal amino acids ranged from 9 to 35 micromoles per gram of protein. At least two polypeptide chains are indicated, with an average molecular weight less than the size of the total protein moiety of the parent lipoprotein. This is consistent with reported physical measurements in formic acid. The three lipoprotein fractions are indistinguishable on the basis of their terminal amino acids.

Metathesis Polymerization of Phenylacetylene by Tungsten Aryloxo Complexes

1995 ◽  
Vol 60 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Hynek Balcar ◽  
Jan Sedláček ◽  
Marta Pacovská ◽  
Vratislav Blechta
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Induction Period ◽  
Average Molecular Weight ◽  
Molar Fraction ◽  
Molar Ratio ◽  
Weight Average Molecular Weight ◽  
Polymer Yield ◽  
Positive Effect ◽  
Ligand Addition

Catalytic activity of the tungsten aryloxo complexes WCl5(OAr) and WOCl3(OAr), where Ar = 4-t-C4H9C6H4, 2,6-(t-C4H9)2C6H3, 2,6-Cl2C6H3, 2,4,6-Cl3C6H2, and 2,4,6-Br3C6H2 in polymerization of phenylacetylene (20 °C, monomer to catalyst molar ratio = 1 000) was studied. The activity of WCl5(OAr) as unicomponent catalysts increases with increasing electron withdrawing character of the -OAr ligand. Addition of two equivalents of organotin cocatalysts (Me4Sn, Bu4Sn, Ph4Sn, Bu3SnH) to WCl5(O-C6H2Cl3-2,4 ,6) has only slight positive effect (slightly higher polymer yield and/or molecular weight of poly(phenylacetylene)s was achieved). However, in the case of WOCl3(O-C6H3Cl2-2, 6) catalyst, it enhances the activity considerably by eliminating the induction period. Poly(phenylacetylene)s prepared with the catalysts studied have weight-average molecular weight ranging from 100 000 to 200 000. They are trans-prevailing and have relatively low molar fraction of monomer units comprised in cyclohexadiene sequences (about 6%).

Characterization of glycopeptides derived from the low-density lipoprotein of hen's egg yolk

1968 ◽  
Vol 46 (8) ◽  
pp. 983-988 ◽  
Author(s):  
J. Z. Augustyniak ◽  
W. G. Martin
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Egg Yolk ◽  
Low Density ◽  
Amide Nitrogen ◽  
Acetylneuraminic Acid ◽  
Hen’S Egg ◽  
Terminal Amino ◽  
Protein Moiety

Two glycopeptides (A and B) were isolated from pronase-digested vitellenin, the protein moiety of the low-density lipoprotein of hen's egg yolk. Aspartic acid was the only N-terminal amino acid of both glycopeptides but only A contained N-acetylneuraminic acid. A contained 55% hexose (mannose), 14% hexosamine, 12% N-acetylneuraminic acid, 0.71% amide nitrogen, and its molecular weight was 2.3 × 103. The corresponding values for B were 64, 17, 0.0, 0.75, and 2.0 × 103. Chemical analyses showed that B (and probably A) occurs in vitellenin with the heteropolysaccharide group bound N-glycosidically via the β-amide group of an asparaginyl residue. The indicated structure is R∙(NH)Asp∙Thr∙Ser∙(Ala, Gly, Val)∙Ile, where R, the heteropolysaccharide group, contains 2 hexosamine and 8 hexose residues.

scholarly journals Characterisation of Sequential Solvent Fractionation and Base-catalysed Depolymerisation of Treated Alkali Lignin

BioResources ◽  
2015 ◽  
Vol 10 (3) ◽  
pp. 4137-4151 ◽  
Author(s):  
Aikfei Ang ◽  
Zaidon Ashaari ◽  
Edi Suhaimi Bakar ◽  
Nor Azowa Ibrahim
Keyword(s):  
Molecular Weight ◽  
Chemical Structure ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Solubility Parameters ◽  
Low Molecular Weight ◽  
Sequential Fractionation ◽  
Weight Average Molecular Weight ◽  
Solvent Fractionation ◽  
Alkali Lignin

An alkali lignin (OL) with a weight-average molecular weight (Mw) of 11646 g/mol was used to prepare low-molecular weight lignin for resin synthesis. The low-molecular weight lignin feedstock was obtained via base-catalysed depolymerisation (BCD) treatments at different combined severity factors. Sequential fractionation of the OL and BCD-treated lignins using organic solvents with different Hildebrand solubility parameters were used to alter the homogeneity of the OL. The yield and properties of OL itself and OL and BCD-treated OL dissolved in propan-1-ol (F1), ethanol (F2), and methanol (F3) were determined. Regardless of the treatment applied, a small amount of OL was dissolved in F1 and F2. The BCD treatment did not increase the yield of F1 but did increase the yields of F2 and F3. Gel permeation chromatography (GPC) showed that the repolymerization reaction occurred in F3 for all BCD-treated OL, so these lignins were not suitable for use as feedstocks for resin production. The GPC, 13Carbon-nuclear magnetic resonance, and Fourier transform infrared spectroscopy analyses confirmed that the F3 in OL exhibited the optimum yield, molecular weight distribution, and chemical structure suitable for use as feedstocks for resin synthesis.

scholarly journals Influence of Dextransucrase of Weissella Cibaria Nitcsk4 on Low Molecular Weight Dextran Yield: a Statistical Approach using Mixed Level Taguchi Design and Artificial Neural Network

2019 ◽  
Vol 9 (2S2) ◽  
pp. 657-664
Keyword(s):  
Neural Network ◽  
Molecular Weight ◽  
Mean Squared Error ◽  
Sucrose Concentration ◽  
Average Molecular Weight ◽  
Taguchi Design ◽  
Percentage Error ◽  
Low Molecular Weight ◽  
Weight Average Molecular Weight ◽  
Weissella Cibaria

In the present study, the influence of dextransucrase of Weissella cibaria NITCSK4 (DSWc4), sucrose concentration, and reaction temperature on the yield of low molecular weight dextran (LMWD-DexWc4) was investigated using mixed level Taguchi design and back propagation neural network (BPNN). BPNN model with three neurons in a hidden layer generated a low mean squared error (MSE). The determination coefficients (R2 -value) for ANN and Taguchi models were 0.991 and 0.998, respectively. Considering absolute average deviation (AAD) and MSE, Taguchi model is more adequate. Among three factors, the percentage yield of low molecular weight of dextran is invariably dependent on the sucrose concentration. The study suggested that a low sucrose concentration (3% w/v), DSWc4 (0.25 IU/ml) and slightly high temperature (35°C) ultimately favored the production of LMWD-DexWc4 (91.639%). LMW-DexWc4 produced by DSWc4 at optimized conditions was analyzed. The weight average molecular weight of LMW-DexWc4 was calculated using M-H expression, found to be 85775 (≈90 kDa). The relative percentage error between the number and weight average molecular weight was found to be less (4.42%). The polydispersity (PD) index of the LMW-DexWc4 was found to be 0.9576 and the value is close to 1. The PD value depicted that the molecular weight distribution of dextran was narrowly dispersed.

Sign in / Sign up

Export Citation Format

Share Document