Studies on Microcapsules. XII. Preparation and Characterization of Carboxylated Polyphthalamide Microcapsules

Characterization was made on the sulfonated polyphthalamide microcapsules (SPPAM) prepared by making use of the interfacial polycondensation reaction of p-phthaloyl dichloride with mixtures of 4,4′-diaminostilbene-2,2′-disulfonic acid and diethylenediamine of varying mole ratios. The specific conductance of dialyzed dispersions of the H form of SPPAM in water was always higher than that of Na form microcapsule dispersions.On the other hand, the former dispersions invariably gave a much lower pH in comparison with the latter. Cation binding experiments established increasing orders, Ca2+ < Sr2+ < Ba2+ and Li+ < K+, NH4+, Na+ < Cs +, for the binding of di-and monovalent cations to SPPAM, respectively. The results were interpreted as showing that less hydrated ions are easier to adsorb on the negatively charged microcapsules. Finally, the feasibility of using SPPAM as ion-exchanger was indicated.

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Synthesis and characterization of novel optically active poly(ester-imide-imine)s

e-Polymers ◽

10.1515/epoly.2009.9.1.122 ◽

2009 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Abdol Reza Hajipour ◽

Parniyan Roosta ◽

Saeed Zahmatkesh ◽

Arnold E. Ruoho

Keyword(s):

Amino Acids ◽

Acetic Acid ◽

Glacial Acetic Acid ◽

Optically Active ◽

Synthesis And Characterization ◽

Interfacial Polycondensation ◽

Thermal Stabilities ◽

Amino Phenol ◽

High Yields

Abstract N,N´-(3,3´,4,4´-Benzophenonetetracarboxylic)-3,3´,4,4´-diimido-di-Lamino acids (1a-1d) and N,N´-pyromelliticdiimido-di-L-amino acids (2a-2d) are prepared from the reaction of 3,3´,4,4´-benzenetetracarboxylic-3,3´,4,4´- dianhydride or pyromellitic dianhydride with the corresponding L-amino acids in a solution of glacial acetic acid/pyridine (3:2) at refluxing temperature. 4-(4-((4- Hydroxyphenylimino)methyl)benzylidene amino) phenol (3) is prepared from 4- amino phenol and terephthaldialdehyde in refluxing ethanol. Interfacial polycondensation method was used to prepare the corresponding polymers (PEII1-8) in two immiscible solvents (water/dichloromethane). The resulting poly(esterimide- imine)s (PEIIs) having good inherent viscosities (0.13-1.25 dl g-1), optical activity and thermal stabilities is obtained in high yields.

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Characterization of the yeast KEX1 gene product: a carboxypeptidase involved in processing secreted precursor proteins.

Molecular and Cellular Biology ◽

10.1128/mcb.9.6.2706 ◽

1989 ◽

Vol 9 (6) ◽

pp. 2706-2714 ◽

Cited By ~ 55

Author(s):

A Cooper ◽

H Bussey

Keyword(s):

Amino Acids ◽

Gene Product ◽

Killer Toxin ◽

Secreted Protein ◽

Serine Carboxypeptidase ◽

Carboxypeptidase B ◽

Basic Amino Acids ◽

Precursor Proteins ◽

In Cells

We have identified and partially characterized the Saccharomyces cerevisiae KEX1 gene product, Kex1p, to assess its role in processing secreted protein precursors. Anti-Kex1p antibodies identified a 113-kilodalton protein that was absent in cells in which the KEX1 gene has been disrupted and that was more abundant in cells overexpressing the KEX1 gene. Kex1p was found to be a membrane-associated glycoprotein with N-linked carbohydrate. The N-linked oligosaccharide(s) was modified in a progressive manner after synthesis, causing the glycoprotein to slowly increase in mass to 115 kilodaltons. After a Kex2p-mediated cleavage event at specific pairs of basic amino acids, alpha-factor and K1 killer toxin precursors have COOH-terminal dibasic residue extensions and require a carboxypeptidase B-like enzyme to process the precursors to maturity. A carboxypeptidase activity, with apparent specificity for basic amino acids, was detected in KEX1 cells. Disruption of the KEX1 gene abolished this activity, while overexpression of KEX1 increased it. Our results provide biochemical evidence consistent with earlier genetic work, that KEX1 encodes a serine carboxypeptidase involved in the processing of precursors to secreted mature proteins.

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A comprehensive survey of the acid-stable fluorescent cross-links formed by ribose with basic amino acids, and partial characterization of a novel Maillard cross-link

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology ◽

10.1016/0167-4838(96)00082-9 ◽

1996 ◽

Vol 1297 (1) ◽

pp. 9-16 ◽

Cited By ~ 16

Author(s):

Lila Graham

Keyword(s):

Amino Acids ◽

Partial Characterization ◽

Cross Link ◽

Basic Amino Acids ◽

Comprehensive Survey ◽

Cross Links ◽

Acid Stable

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Preparation and Characterization of Acrylic Hydrogels Neutralized by Basic Amino Acids.

Chemical and Pharmaceutical Bulletin ◽

10.1248/cpb.48.1828 ◽

2000 ◽

Vol 48 (11) ◽

pp. 1828-1830 ◽

Cited By ~ 2

Author(s):

Takahiro UCHIDA ◽

Yuka TOIDA ◽

Yohko MIYANAGA ◽

Kotoe MACHIDA ◽

Koichi WADA ◽

...

Keyword(s):

Amino Acids ◽

Basic Amino Acids

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Experimental Studies on n-Octane and Cyclohexane as Organic Solvent for Synthesis of Polyurea Microcapsules by Interfacial Polycondensation

Asian Journal of Engineering and Applied Technology ◽

10.51983/ajeat-2018.7.2.1006 ◽

2018 ◽

Vol 7 (2) ◽

pp. 64-66

Author(s):

Ujvala P. Christian ◽

Shrikant J. Wagh

Keyword(s):

Organic Solvent ◽

Reaction Rate ◽

Experimental Studies ◽

Reaction System ◽

Large Mass ◽

Interfacial Polycondensation ◽

Good Thermal Stability ◽

Kinetics Of ◽

Selection Of

Interfacial polycondensation (IP) is one of the most important step polymerization technique used for synthesis of polyurea microcapsules. IP reaction between diamine and diisocyanate monomers which are soluble in aqueous phase and organic phase respectively is very fast therefore the overall process of polyurea synthesis via interfacial polycondensation, by and large, mass transfer controlled reaction. Selection of proper organic solvent is one of the important parameter for IP reactions. The objective of this experimental work was to study the effect of n-Octane and Cyclohexane as an organic solvent on kinetics of polyurea microcapsules synthesized by interfacial polycondensation reaction. In this reaction system IP reaction occurs on organic side of the interface so reaction rate increased with increase in relative polarity of organic solvent. Characterization of polyurea was carried out by XRD and DSC which demonstrated that semi crystalline polyurea microcapsules with good thermal stability were synthesized.

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Characterization of the yeast KEX1 gene product: a carboxypeptidase involved in processing secreted precursor proteins

Molecular and Cellular Biology ◽

10.1128/mcb.9.6.2706-2714.1989 ◽

1989 ◽

Vol 9 (6) ◽

pp. 2706-2714

Author(s):

A Cooper ◽

H Bussey

Keyword(s):

Amino Acids ◽

Gene Product ◽

Killer Toxin ◽

Secreted Protein ◽

Serine Carboxypeptidase ◽

Carboxypeptidase B ◽

Basic Amino Acids ◽

Precursor Proteins ◽

In Cells

We have identified and partially characterized the Saccharomyces cerevisiae KEX1 gene product, Kex1p, to assess its role in processing secreted protein precursors. Anti-Kex1p antibodies identified a 113-kilodalton protein that was absent in cells in which the KEX1 gene has been disrupted and that was more abundant in cells overexpressing the KEX1 gene. Kex1p was found to be a membrane-associated glycoprotein with N-linked carbohydrate. The N-linked oligosaccharide(s) was modified in a progressive manner after synthesis, causing the glycoprotein to slowly increase in mass to 115 kilodaltons. After a Kex2p-mediated cleavage event at specific pairs of basic amino acids, alpha-factor and K1 killer toxin precursors have COOH-terminal dibasic residue extensions and require a carboxypeptidase B-like enzyme to process the precursors to maturity. A carboxypeptidase activity, with apparent specificity for basic amino acids, was detected in KEX1 cells. Disruption of the KEX1 gene abolished this activity, while overexpression of KEX1 increased it. Our results provide biochemical evidence consistent with earlier genetic work, that KEX1 encodes a serine carboxypeptidase involved in the processing of precursors to secreted mature proteins.

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Isolation and partial characterization of a peptidase with trypsin-like activity from bovine adenohypophysis

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19892276 ◽

1989 ◽

Vol 54 (8) ◽

pp. 2276-2286

Author(s):

Tsezengijn Dash ◽

Tomislav Barth ◽

Jiřina Slaninová ◽

Jana Barthová ◽

Hana P. Mašková ◽

...

Keyword(s):

Amino Acids ◽

Molecular Weight ◽

Partial Characterization ◽

Chromogenic Substrate ◽

Fluorogenic Substrate ◽

Basic Amino Acids ◽

Optimum Ph ◽

Reproducible Method ◽

Hydrolysis Of

A reproducible method has been developed for the isolation of the adenohypophyseal enzyme with a trypsin-like activity. The enzyme is able to hydrolyze Nα-benzoyl-L-arginine-p-nitroanilide, a fluorogenic substrate CBzl-Arg-Arg-β-naphthyl amide and some peptides with one or two accumulated basic amino acids in the chain. The optimum pH for hydrolysis of the chromogenic substrate was within the range 6.0-7.0 (Km = 0.66 mmol l-1), in the case of the fluorogenic substrate the range was between 7.0 and 7.5 (Km = 1.2 μmol l-1). The enzyme is activated by cysteine and dithiothreitol and inhibited by SH-poisons. The molecular weight of the enzyme, determined by means of two independent methods, was approximately 25 kDA.

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