Iron(III) complexes of DL-methionine

1972 ◽  
Vol 25 (2) ◽  
pp. 421 ◽  
Author(s):  
EJ Halbert ◽  
MJ Rogerson
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Large Excess ◽  
Ph Titration ◽  
Oxidation Reduction ◽  
Infrared Studies ◽  
Rapid Hydrolysis ◽  
Iron Analysis ◽  
Hydrolysis Of ◽  
Made In

Few iron(111) complexes of amino acids have been isolated although attempts have been made to measure their stabilities in solution. Iron(111) in the presence of various amino acids showed no complex formation during pH titration in aqueous solution. Using oxidation-reduction and spectrophotometric techniques Perrin measured the stabilities of 1 : 1 complexes of iron(111) with different amino acids in solutions of low pH. Rapid hydrolysis of iron(111) occurred when the pH was increased even in the presence of a large excess of amino acids. Bielig and Bayer reported the isolation of a bis-complex of iron(111) and methionine prepared in aqueous solution. McAuliffe, Quagliano, and Vallarinoe reported a tris-complex made in ethanol, though their iron analysis was not consistent with the required structure. In both cases magnetic and infrared studies were used to characterize the products. Our attempts to repeat these preparations were unsuccessful. This paper describes the preparation of two 1 : 1 complexes of methionine and iron(111) and an investigation of their properties by analysis of infrared, magnetic, and N.M.R. measurements.

Hydrolysis of Cinnamaldehyde in Aqueous Solution at Room Temperature Catalyzed by Amino Acids

2012 ◽  
Vol 512-515 ◽  
pp. 2361-2365 ◽  
Author(s):  
Lu Lu Huang ◽  
Xing Dong Yao ◽  
Yong Peng An ◽  
Cai Hua Peng
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Reaction Time ◽  
Room Temperature ◽  
Spectroscopic Analysis ◽  
Buffer Concentration ◽  
Hydrolysis Of

The hydrolysis of cinnamaldehyde in aqueous solution catalyzed by amino acids has been investigated. Eight amino acids e.g. glycine, proline etc. have been employed as the small molecular organocatalysts. The effect of reaction time, temperature, buffer concentration on the reaction has been studied. Spectroscopic analysis indicated the reaction product is 3-hydroxy-3-phenylpropanal.

Attempting to rewrite History: challenges with the analysis of histidine-phosphorylated peptides

2013 ◽  
Vol 41 (4) ◽  
pp. 1089-1095 ◽  
Author(s):  
Maria-Belen Gonzalez-Sanchez ◽  
Francesco Lanucara ◽  
Matthew Helm ◽  
Claire E. Eyers
Keyword(s):  
Amino Acids ◽  
Protein Function ◽  
Biologically Relevant ◽  
Phosphorylated Peptides ◽  
Higher Eukaryotes ◽  
Histidine Phosphorylation ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of ◽  
Acid Labile

A significant number of proteins in both eukaryotes and prokaryotes are known to be post-translationally modified by the addition of phosphate, serving as a means of rapidly regulating protein function. Phosphorylation of the amino acids serine, threonine and tyrosine are the focus of the vast majority of studies aimed at elucidating the extent and roles of such modification, yet other amino acids, including histidine and aspartate, are also phosphorylated. Although histidine phosphorylation is known to play extensive roles in signalling in eukaryotes, plants and fungi, roles for phosphohistidine are poorly defined in higher eukaryotes. Characterization of histidine phosphorylation aimed at elucidating such information is problematic due to the acid-labile nature of the phosphoramidate bond, essential for many of its biological functions. Although MS-based strategies have proven extremely useful in the analysis of other types of phosphorylated peptides, the chromatographic procedures essential for such approaches promote rapid hydrolysis of phosphohistidine-containing peptides. Phosphate transfer to non-biologically relevant aspartate residues during MS analysis further complicates the scenario.

scholarly journals Vanadium(III) binding strengths of small biomolecules

2005 ◽  
Vol 77 (9) ◽  
pp. 1583-1594 ◽  
Author(s):  
Péter Buglyó ◽  
Eszter Márta Nagy ◽  
Imre Sóvágó
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Ionic Strength ◽  
Metal Ion ◽  
Donor Ligands ◽  
Spectroscopic Techniques ◽  
Hydroxo Complexes ◽  
Similarities And Differences ◽  
Small Biomolecules ◽  
Hydrolysis Of

The hydrolysis of vanadium(III) and the complex formation reactions between V(III) and weakly coordinating [glycine (GLY), DL-aspartic acid (ASP), D-penicillamine (PEN), DL-histidine (HIS)] or strongly coordinating [N,O] donor [picolinic (PIC) or 6-methylpicolinic acid (MePIC)] and [O,O] donor [maltol (MALT), 1,2-dimethyl-3-hydroxy-4-(1H)-pyridinone (DHP), tiron (TIR)] ligands were studied at 25.0 °C and an ionic strength of 0.20 M (KCl) in aqueous solution using combined pH-potentiometric and UV-vis spectroscopic techniques. Although some interaction between the amino acids and V(III) was found, we could not obtain reliable models for these systems owing to the intensive hydrolysis of the metal ion and the formation of polynuclear hydroxo complexes. With pyridine carboxylates or [O,O] donor ligands 1:1, 1:2 (in the latter case, also 1:3 species) were found to be present as major complexes in solution. The similarities and differences in binding V(III) by these ligands are discussed.

scholarly journals Some investigations dealing with the state of aggregation of matter.—Parts I-III

1910 ◽  
Vol 83 (562) ◽  
pp. 96-123 ◽  
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Amino Acid ◽  
General Equation ◽  
The State ◽  
Large Excess ◽  
Satisfactory Explanation

During the course of some investigations on the action of formaldehyde on the proteins, the observation was made that this aldehyde, when added to an aqueous solution of Witte's peptone, produces a precipitate, and that the reaction could be either partially or completely inhibited by the presence of neutral salts. This phenomenon was also noticed some years ago by T. Sollman, who offered no satisfactory explanation of the facts. The more recent investigations of Sörensen have shown that when formaldehyde reacts with amino-acids a methyleneimino-derivative is produced, which is readily hydrolysed in the presence of water, yielding the original amino-acid and formaldehyde. The reaction is therefore a reversible one, and can be represented by the general equation (NH 2 ) R·COOH + HCHO ⇌ (CH:N) R·COOH + H 2 O. The amino-acid is only completely converted into the methyleneimino-derivative in the presence of a large excess of formaldehyde, and the methyleneimino-acid thus produced is, in contrast to the amino-acid from which it was formed, so strongly acid that it can be titrated with caustic alkalis in the presence of phenolphthalein as indicator. These results are an extension and application of those which had been obtained some years before by Schiff.

scholarly journals Deacylation of acylamino compounds other than penicillins by the cell-bound penicillin acylase of Escherichia coli

1969 ◽  
Vol 115 (4) ◽  
pp. 741-745 ◽  
Author(s):  
M. Cole
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Small Group ◽  
Penicillin Acylase ◽  
E Coli ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of

1. The action of the penicillin acylase enzyme of Escherichia coli N.C.I.B. 8743 on non-penicillin substrates suggests that the enzyme is an amidohydrolase. 2. The rates of hydrolysis for a small group of penicillins closely parallel those for a corresponding series of N-acylglycines. 3. For a series of E. coli strains, ability to cause rapid hydrolysis of phenylacetylglycine is correlated with ability to hydrolyse benzylpenicillin. 4. Amides and N-acylglycines are hydrolysed to the corresponding acids. The phenylacetyl group is hydrolysed most readily. Benzamide and β-phenylpropionamide are not substrates. In a series of aliphatic acylglycines only valeryl- and hexanoyl-glycine are substrates. 5. Acylated l- but not d-α-amino acids are hydrolysed. d-α-Hydroxyphenylacetamide is a better substrate than the l compound.

scholarly journals Catalytic Hydrolysis of Phosphate Monoester by Supramolecular Complexes Formed by the Self-Assembly of a Hydrophobic Bis(Zn2+-cyclen) Complex, Copper, and Barbital Units That Are Functionalized with Amino Acids in a Two-Phase Solvent System

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 452
Author(s):  
Yuya Miyazawa ◽  
Akib Bin Rahman ◽  
Yutaka Saga ◽  
Hiroki Imafuku ◽  
Yosuke Hisamatsu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Active Site ◽  
Self Assembly ◽  
Hydrolytic Activity ◽  
Solvent System ◽  
Supramolecular Complexes ◽  
Artificial System ◽  
Two Phase ◽  
Hydrolysis Of

We previously reported on the preparation of supramolecular complexes by the 2:2:2 assembly of a dinuclear Zn2+-cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) complex having a 2,2′-bipyridyl linker equipped with 0~2 long alkyl chains (Zn2L1~Zn2L3), 5,5-diethylbarbituric acid (Bar) derivatives, and a copper(II) ion (Cu2+) in aqueous solution and two-phase solvent systems and their phosphatase activities for the hydrolysis of mono(4-nitrophenyl) phosphate (MNP). These supermolecules contain Cu2(μ-OH)2 core that mimics the active site of alkaline phosphatase (AP), and one of the ethyl groups of the barbital moiety is located in close proximity to the Cu2(μ-OH)2 core. The generally accepted knowledge that the amino acids around the metal center in the active site of AP play important roles in its hydrolytic activity inspired us to modify the side chain of Bar with various functional groups in an attempt to mimic the active site of AP in the artificial system, especially in two-phase solvent system. In this paper, we report on the design and synthesis of new supramolecular complexes that are prepared by the combined use of bis(Zn2+-cyclen) complexes (Zn2L1, Zn2L2, and Zn2L3), Cu2+, and Bar derivatives containing amino acid residues. We present successful formation of these artificial AP mimics with respect to the kinetics of the MNP hydrolysis obeying Michaelis–Menten scheme in aqueous solution and a two-phase solvent system and to the mode of the product inhibition by inorganic phosphate.

scholarly journals Simultaneous Presence of PrtH and PrtH2 Proteinases inLactobacillus helveticusStrains Improves Breakdown of the Pure αs1-Casein

2010 ◽  
Vol 77 (1) ◽  
pp. 179-186 ◽  
Author(s):  
L. Sadat-Mekmene ◽  
J. Jardin ◽  
C. Corre ◽  
D. Mollé ◽  
R. Richoux ◽  
...  
Keyword(s):  
Amino Acids ◽  
Cell Envelope ◽  
Sodium Dodecyl ◽  
Lactobacillus Helveticus ◽  
Whole Cells ◽  
Proteolytic Activities ◽  
Rapid Hydrolysis ◽  
Milk Casein ◽  
Kinetics Of ◽  
Hydrolysis Of

ABSTRACTLactobacillus helveticuscan possess one or two cell envelope proteinases (CEPs), called PrtH2 and PrtH. The aim of this work was to explore the diversity of 15 strains ofL. helveticus, isolated from various origins, in terms of their proteolytic activities and specificities on pure caseins or on milk casein micelles. CEP activity differed 14-fold when the strains were assayed on a synthetic substrate, but no significant differences were detected between strains possessing one or two CEPs. No correlation was observed between the proteolytic activities of the strains and their rates of acidification in milk. The kinetics of hydrolysis of purified αs1- and β-casein byL. helveticuswhole cells was monitored using Tris-Tricine sodium dodecyl sulfate (SDS) electrophoresis, and for four strains, the peptides released were identified using mass spectrometry. While rapid hydrolysis of pure β-casein was observed for all strains, the hydrolysis kinetics of αs1-casein was the only criterion capable of distinguishing between the strains based on the number of CEPs. Fifty-four to 74 peptides were identified for each strain. When only PrtH2 was present, 22 to 30% of the peptides originated from αs1-casein. The percentage increased to 41 to 49% for strains in which both CEPs were expressed. The peptide size ranged from 6 to 33 amino acids, revealing a broad range of cleavage specificities, involving all classes of amino acids (Leu, Val, Ala, Ile, Glu, Gln, Lys, Arg, Met, and Pro). Regions resistant to proteolysis were identified in both caseins. When strains were grown in milk, a drastic reduction in the number of peptides was observed, reflecting changes in accessibility and/or peptide assimilation during growth.

Hydrolysis of Proteins for Amino Acid Analysis. II. Acid Hydrolysis in Sealed Tubes of Mixtures of β-Lactoglobulin and Starch

1964 ◽  
Vol 47 (4) ◽  
pp. 745-747 ◽  
Author(s):  
William G Gordon ◽  
Jay J Basch
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Hydrolysis ◽  
Amino Acid Analysis ◽  
Special Method ◽  
Large Excess ◽  
Β Lactoglobulin ◽  
Hydrolysis Of

Abstract Experiments with a mixture of β-Iactoglobulin and starch, simulating the composition of carbohydrate-rich foods and feeds, have been carried out to determine conditions for acid hydrolysis that will permit maximal recovery of amino acids in hydrolysates of such materials. When a large excess of 6N HC1 is used for hydrolysis, good recoveries of most amino acids are obtained. However, about one-quarter of the tyrosine present is destroyed under the conditions investigated. Some destruction of methionine and cystine may also be attributed to the presence of carbohydrate, but a special method for the determination of these amino acids is available.

Pengoptimalan Air Leri dalam Pembuatan Sabun Pembersih Wajah Alami yang Ekonomis

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Rahmawati Rahmawati ◽  
Trimayasari Trimayasari ◽  
Ghozali Akhmad Mustaqim ◽  
Wening Dwi Prastiwi ◽  
Emas Agus Prastyo Wibowo
Keyword(s):  
Amino Acids ◽  
Fine Particles ◽  
Hard Water ◽  
Essential Amino Acids ◽  
Ultraviolet Rays ◽  
Starch Granules ◽  
Facial Skin ◽  
Skin Cells ◽  
The Face ◽  
Made In

AbstractSoap facial cleanser is needed to keep the facial skin to keep them clean and healthy. The purpose of this study to make soap cleanser with natural materials such as hard water deposits leri. This is because the use of leri water starch or starch granules of fine particles contained in water leri dansel dust can shed the dead skin on the face because of the essential amino acids contained can regenerate skin cells. In addition, water leri can brighten the face because the leri water oryzanol contain substances that can update the development and formation of the pigment melanin, which is effectively to ward off ultraviolet rays. The process of making soap using the principle of saponification reaction, namely the reaction between the oil and the KOH/NaOH. Facial cleansing soap made in this study is solid soap. Based on the results of quality test, soap solid leri water has a pH of 11.1, saponification number is 33, the water content of 46% as well as respondents to the test aspects of aroma and foam shows good results so this water leri treatment can be an alternative solution to prevent the use of soap facial cleansers that contain harmful chemicals. Keywords: air leri, soap cleanser, saponification  AbstrakSabun pembersih wajah sangat diperlukan untuk menjaga kulit wajah agar tetap bersih dan sehat. Tujuan dari penelitian ini untuk membuat sabun pembersih wajah dengan bahan alami berupa endapan air leri. Penggunaan air leri ini dikarenakan butiran partikel starch atau pati halus yang terdapat dalam air leri dapat merontokkan debu dansel kulit mati pada wajah karena asam amino esensial yang terkandung dapat meregenerasi sel-sel kulit. Selain itu, air leri dapat mencerahkan wajah karena air leri mengandung zat oryzanol yang dapat memperbarui perkembangan dan pembentukan pigmen melanin, yang efektif guna menangkal sinar ultraviolet. Proses pembuatan sabun menggunakan prinsip reaksi saponifikasi, yaitu reaksi antara minyak dan KOH/NaOH. Sabun pembersih wajah yang dibuat dalam penelitian ini ialah sabun padat. Berdasarkan hasil uji mutu, sabun air leri padat memiliki pH 11,1, angka penyabunan sebesar 33 kadar air 46 kadar air 46 % serta uji responden terhadap aspek aroma dan busa yang menunjukkan hasil cukup baik sehingga pengolahan air leri ini dapat menjadi solusi alternative untuk mencegah penggunaan sabun pembersih wajah yang mengandung bahan kimia berbahaya. Kata kunci: air leri, sabun pembersih wajah, saponifikasi 

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