A spectrophotometric assay for solid phase primary amino groups

1992 ◽  
Vol 36 (2) ◽  
pp. 81-85 ◽  
Author(s):  
Violeta G. Janolino ◽  
Harold E. Swaisgood
Keyword(s):  
Solid Phase ◽  
Spectrophotometric Assay ◽  
Amino Groups ◽  
Primary Amino

Two different approaches for developing immunometric assays of haptens

1996 ◽  
Vol 42 (9) ◽  
pp. 1532-1536 ◽  
Author(s):  
J Grassi ◽  
C Créminon ◽  
Y Frobert ◽  
E Etienne ◽  
E Ezan ◽  
...  
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibody ◽  
Solid Phase ◽  
Leukotriene C4 ◽  
Amino Groups ◽  
Small Peptides ◽  
Assay Sensitivity ◽  
Primary Amino ◽  
C And N

Abstract To improve immunoassays of small haptens, we developed two different approaches for their measurement in a non-competitive format. We first devised two-site immunometric assays for small peptides (8-11 amino acids) by selecting two sets of antibodies specifically directed against C- and N-terminal moieties of the peptides. In each case, assay sensitivity improved substantially over that of the corresponding competitive assays. More interestingly, all of these new immunometric assays were much more specific than the competitive assays. In a second approach, we developed a new procedure, solid-phase-immobilized epitope immunoassay (SPIE-IA), in which a single monoclonal antibody uses the same epitope for capture and tracer binding and the hapten is covalently cross-linked to solid-phase proteins. To date, SPIE-IA have been successfully applied to the determination of haptens bearing primary amino groups, including substance P, thyroxine, leukotriene C4, endothelin, and angiotensin II. In each case, assay sensitivity was significantly improved.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

Purification of Penicillin Amidohydrolase, an Enzyme for Semisynthetic Procedures

1992 ◽  
Vol 57 (10) ◽  
pp. 2187-2191 ◽  
Author(s):  
Jiří Jiráček ◽  
Tomislav Barth ◽  
Jiří Velek ◽  
Ivo Bláha ◽  
Jan Pospíšek ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Amino Groups ◽  
Primary Amino

Penicillin amidohydrolase (EC 3.5.1.11.) is one of the few enzymes used successfully for deprotection of primary amino groups of semisynthetic peptides. The available material is usually contamined by endo- and exopeptidases. We managed to prepare the enzyme devoid of trypsin- and chymotrypsin-like activities using affinity chromatography with specific ligands: Gly-D-Phe-Phe-Tyr-Thr-Pro-Lys-Thr (the fF peptide) and Leu-Gly-Val-D-Arg-Arg-Gly-Phe (the rR peptide). For further purification of the enzyme affinity chromatography with N-phenylacetyl-D-tert-Leu as a ligand was used.

scholarly journals Competitive Biological Activities of Chitosan and Its Derivatives: Antimicrobial, Antioxidant, Anticancer, and Anti-Inflammatory Activities

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Suyeon Kim
Keyword(s):  
Water Solubility ◽  
Biological Activities ◽  
Biological Properties ◽  
Biomedical Science ◽  
Amino Groups ◽  
Chitosan Oligosaccharides ◽  
Primary Amino ◽  
Anti Inflammatory ◽  
Key Functional Groups ◽  
Application Fields

Chitosan is obtained from alkaline deacetylation of chitin, and acetamide groups are transformed into primary amino groups during the deacetylation. The diverse biological activities of chitosan and its derivatives are extensively studied that allows to widening the application fields in various sectors especially in biomedical science. The biological properties of chitosan are strongly depending on the solubility in water and other solvents. Deacetylation degree (DDA) and molecular weight (MW) are the most decisive parameters on the bioactivities since the primary amino groups are the key functional groups of chitosan where permits to interact with other molecules. Higher DDA and lower MW of chitosan and chitosan derivatives demonstrated higher antimicrobial, antioxidant, and anticancer capacities. Therefore, the chitosan oligosaccharides (COS) with a low polymerization degree are receiving a great attention in medical and pharmaceutical applications as they have higher water solubility and lower viscosity than chitosan. In this review articles, the antimicrobial, antioxidant, anticancer, anti-inflammatory activities of chitosan and its derivatives are highlighted. The influences of physicochemical parameters of chitosan like DDA and MW on bioactivities are also described.

scholarly journals Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

2014 ◽  
Vol 10 ◽  
pp. 2729-2737 ◽  
Author(s):  
Gerald Jarre ◽  
Steffen Heyer ◽  
Elisabeth Memmel ◽  
Thomas Meinhardt ◽  
Anke Krueger
Keyword(s):  
Diels Alder ◽  
Amino Groups ◽  
Pyrimidine Derivatives ◽  
Quantification Method ◽  
Different Types ◽  
Primary Amino ◽  
Wet Chemical ◽  
Terminal Amino ◽  
Chemical Quantification

Nanodiamonds functionalized with different organic moieties carrying terminal amino groups have been synthesized. These include conjugates generated by Diels–Alder reactions of ortho-quinodimethanes formed in situ from pyrazine and 5,6-dihydrocyclobuta[d]pyrimidine derivatives. For the quantification of primary amino groups a modified photometric assay based on the Kaiser test has been developed and validated for different types of aminated nanodiamond. The results correspond well to values obtained by thermogravimetry. The method represents an alternative wet-chemical quantification method in cases where other techniques like elemental analysis fail due to unfavourable combustion behaviour of the analyte or other impediments.

scholarly journals Role of capping in peptide synthesis

2020 ◽  
Vol 11 (4) ◽  
pp. 5225-5228
Author(s):  
Deepshikha Verma ◽  
Pillai V N R ◽  
Giriraj Tailor
Keyword(s):  
Peptide Synthesis ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Protecting Groups ◽  
Amino Groups ◽  
Peptide Chemistry ◽  
Fmoc Spps ◽  
Reliable Methods ◽  
Important Test

Protecting groups like Fmoc and coupling both steps are essential to monitoring the Fmoc SPPS (Solid Phase Peptide Synthesis) reaction completion. Reliable methods are used to detect the unreacted number of amino groups for monitoring these two essential reaction steps of coupling and cleavage. The ability to detect the complete coupling, incomplete coupling or failure of coupling we use many colour tests in the laboratory and based on this the Fmoc peptide chemistry allows the control of the completion of the Fmoc cleavage. The most important test used is the Kaiser test and highly recommended to monitor the coupling and cleavage steps. If the result of colour tests is positive after coupling, then the second coupling should be performed. Then again use the colour test to detect the level of coupling. If the result is still slightly positive, repeat coupling with the smaller modification of reagents such as used PyBOP instead of HOBT AND HOAT. These colour tests help in revealing the presence of unreacted amino-functional groups. Thus, we need to block these free N-terminal of amino- acids which help in avoiding the making of deletion of sequence.

scholarly journals Sensitive analysis of ethanolamine- and serine-containing phosphoglycerides by high-performance liquid chromatography

1975 ◽  
Vol 145 (3) ◽  
pp. 517-526 ◽  
Author(s):  
F B Jungalwala ◽  
R J Turel ◽  
J E Evans ◽  
R H McCluer
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Limit Of Detection ◽  
High Performance Liquid Chromatographic ◽  
Amino Groups ◽  
Tissue Samples ◽  
Primary Amino ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

A highly sensitive method for the separation and quantitative measurement of phospholipids containing primary amino groups, such as phosphatidylethanolamine, phosphatidylserine and lysophosphatidylethanolamine, is described. The method involves a simple and quantitative derivative formation of the phospholipids containing amino groups to their u.v.-absorbing biphenylcarbonyl derivatives. These have molar extinction coefficients of about 23,000 at 268nm. The phospholipid derivatives are then separated and non-destructively determined by high-performance liquid chromatography. The amino phospholipids containing vinyl ether bonds (plasmalogens) can be determined separately from the diacyl- and alkylacyl-amino phospholipids. The lower limit of detection by high-performance liquid-chromatographic analysis of the phospholipid derivatives is about 10-13pmol or 0.3-0.4ng of phospholipid P. The quantitative range of derivative formation and analysis by high-performance liquid chromatography of the phospholipids containing amino groups was shown to be 10-500nmol. The method was shown to be applicable to the analysis of phospholipids containing amino groups in tissue samples.

Polyacrolein microspheres as a new tool in cell biology

1982 ◽  
Vol 56 (1) ◽  
pp. 157-175
Author(s):  
S. Margel ◽  
U. Beitler ◽  
M. Ofarim
Keyword(s):  
Cell Biology ◽  
Polymerization Process ◽  
Amino Groups ◽  
Ph Values ◽  
Human Red Blood Cells ◽  
Primary Amino ◽  
Aldehyde Groups ◽  
Potential Use ◽  
Specific Labelling ◽  
Reactive Aldehyde

Polyacrolein (PA) microspheres in sizes ranging from 0.04 micron to 40 microns were synthesized. Magnetic and fluorescent PA microspheres were formed by carrying out the polymerization process in the presence of appropriate ferrofluidic or fluorochromic compounds, respectively. The microspheres carry reactive aldehyde groups, through which various ligands, containing primary amino groups, were covalently bound at physiological pH values. The potential use of these microspheres was demonstrated by the specific labelling of fresh human red blood cells (RBC) and by the separation of human RBC from turkey RBC by means of a magnetic field. PA microspheres were also bound covalently to the anti-allergic drug disodium chromoglycate (DSCG) and the conjugate was used for the labelling of rat basophilic leukaemia cells.

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