scholarly journals Dissociation, unfolding and refolding trials of pig kidney 3,4-dihydroxyphenylalanine (dopa) decarboxylase

1993 ◽  
Vol 295 (2) ◽  
pp. 493-500 ◽  
Author(s):  
P Dominici ◽  
P S Moore ◽  
C Borri Voltattorni
Keyword(s):  
Conformational Changes ◽  
Dopa Decarboxylase ◽  
Experimental Conditions ◽  
High Tendency ◽  
Denatured Protein ◽  
Pig Kidney ◽  
Plausible Model ◽  
Spectroscopic Characteristics ◽  
Equilibrium Transition ◽  
Almost All

The effect of guanidinium chloride (GuCl) on enzyme activity, hydrodynamic volume, circular dichroism, and fluorescence of 3,4-dihydroxyphenylalanine (Dopa) decarboxylase from pig kidney (pkDDC) was studied under equilibrium conditions. Unfolding proceeds in at least three stages. The first transition, occurring between 0 and 1 M GuCl, gives rise to a dimeric inactive species which has lost pyridoxal 5′-phosphate (PLP), and has a high tendency to aggregate, but retains almost all of the native spectroscopic characteristics. The second equilibrium transition, between 1 and 2.2 M GuCl, involves dimer dissociation, with some loss of tertiary and secondary structure. Additionally, gross conformational changes at or near the PLP microenvironment were detected by fluorescence of NaBH4-reduced enzyme. The third step, presumably representing complete unfolding of pkDDC, appears to be complete at 4.5 M GuCl, as indicated by the lack of further substantial changes in any of the signals being studied. Attempts at refolding resulted in the findings that: (1) partial reactivation is observed only starting from enzyme denatured at concentrations below 1.5 M GuCl, and (2) starting from completely denatured protein, the refolding process is apparently reversible down to concentrations of approx. 2 M GuCl. Taken together, this would seem to indicate that the monomer-dimer transition is impaired under the experimental conditions tested. A plausible model is presented for the unfolding/refolding of pkDDC.

Pig Kidney DOPA Decarboxylase.

1990 ◽  
Vol 585 (1 Vitamin B6) ◽  
pp. 162-172 ◽  
Author(s):  
PAOLA DOMINICI ◽  
PAOLA FILIPPONI ◽  
MARIA EUGENIA SCHININÀ ◽  
DONATELLA BARRA ◽  
CARLA BORRI VOLTATTORNI
Keyword(s):  
Dopa Decarboxylase ◽  
Pig Kidney

Crystallization and preliminary X-ray analysis of pig kidney DOPA decarboxylase

1992 ◽  
Vol 224 (4) ◽  
pp. 1167-1170 ◽  
Author(s):  
Vladimir N. Malashkevich ◽  
Paola Filipponi ◽  
Ursula Sauder ◽  
Paola Dominici ◽  
Johan N. Jansonius ◽  
...  
Keyword(s):  
Dopa Decarboxylase ◽  
X Ray ◽  
Pig Kidney

DNA Interaction and Biological Activities of Heteroleptic Palladium (II) Complexes

2021 ◽  
Vol 43 (2) ◽  
pp. 227-227
Author(s):  
Muhammad Anwar Saeed Muhammad Anwar Saeed ◽  
Hizbullah Khan Hizbullah Khan ◽  
Muhammad Sirajuddin Muhammad Sirajuddin ◽  
Syed Muhammad Salman Syed Muhammad Salman
Keyword(s):  
Biological Activities ◽  
Thiobarbituric Acid ◽  
Dna Interaction ◽  
Log P ◽  
Bacterial Strains ◽  
Experimental Conditions ◽  
H2o2 Treatment ◽  
Biological Studies ◽  
Almost All ◽  
Anti Fungal

The manuscript describes the binding of DNA as well as biological studies of some mixed ligand dithiocarbamate Palladium (II) complexes (1-5). The observed compounds are of general formulae [PdCl(DT)(PR3)]. The dithiocarbamate “DT” and “PR3” groups are varied among the studied complexes as DT = bis[(2-methoxyethyl) dithiocarbamate)] (1 and 2), dibutyl dithiocarbamate (4 and 5), bis[(2-ethyl) hexyl dithiocarbamate)] (3); PR3 = triphenyl phosphine (1), benzy diphenyl phosphine (2), diphenyl-tert-butyl phpsphine (3), diphenyl-p-tolyl phosphine (4) and diphenyl-2-methoxy phenyl phosphine (5). The synthesized complexes were screened for DNA binding study via (UV Visible spectrophotometry and Viscometery) and biological activities such as anti-bacterial and anti-fungal, Molinspiration calculations and antioxidant potencies stimulated by hydrogen peroxide in human blood lymphocytes. In case of drug DNA interaction, complexes showed some sort of interaction with DNA solution. Almost all the complexes exhibited moderate antifungal and antibacterial behavior (against Gram positive and negative bacterial strains). The Molinspiration calculation study revealed that the said Pd (II) mixed complexes are biologically significant drugs having adequate molecular properties regarding drug likeness, except the log P values of complexes 3-5 because some structural adjustments must be done for enhancement of their bioavailability and hydrophilic nature. Regarding the antioxidant potential of complexes 1, 2 and 4, the H2O2 treatment of complexes violently decreased the action of antioxidant enzymes, superoxide dismutase and catalase and enhanced the level of thiobarbituric acid-reacting substances. Under experimental conditions, we conclude that all complexes act as anti-mutagens as they significantly suppress H2O2-induced oxidative damage at non-genotoxic concentrations.

Linear tetrapyrroles as functional pigments in chemistry and biology

2004 ◽  
Vol 08 (03) ◽  
pp. 226-237 ◽  
Author(s):  
Tadashi Mizutani ◽  
Shigeyuki Yagi
Keyword(s):  
Conformational Changes ◽  
Materials Science ◽  
Redox Activity ◽  
Helical Conformation ◽  
Biological Functions ◽  
Experimental Conditions ◽  
Chiral Structure ◽  
Biliverdin Ix ◽  
Linear Tetrapyrroles ◽  
Single Bonds

1,19,21,24-tetrahydro-1,19-bilindione is the framework of pigments frequently found in nature, which includes biliverdin IX α, phytochromobilin and phycocyanobilin. 1,19-bilindiones have unique features such as (1) photochemical and thermal cis-trans isomerization, (2) excited energy transfer, (3) chiroptical properties due to the cyclic helical conformation, (4) redox activity, (5) coordination to various metals, and (6) reconstitution to proteins. 1,19-bilindione can adopt a number of conformations since it has exocyclic three double bonds and three single bonds that are rotatable thermally and photochemically. In solution, biliverdin and phycocyanobilin adopt a cyclic helical ZZZ, syn, syn, syn conformation, but other conformations are stabilized depending on the experimental conditions and substituents on the bilin framework. The conformational changes in 1,19-bilindiones are related to the biological functions of a photoreceptor protein, phytochrome. Structural and conformational studies of bilindiones are summarized both in solution and in protein. The conformational changes of bilins can be used for other functions such as a chirality sensor. The bilindiones and the zinc complexes of bilindiones can be employed as a chirality sensor due to the helically chiral structure and the dynamics of racemization of enantiomers. In this paper, we discuss the conformational equilibria and dynamics of bilindiones and its implications in photobiology and materials science.

scholarly journals Pig kidney 3,4-dihydroxyphenylalanine (Dopa) decarboxylase. Primary structure and relationship to other amino acid decarboxylases

1991 ◽  
Vol 201 (2) ◽  
pp. 385-391 ◽  
Author(s):  
Bruno MARAS ◽  
Paola DOMINICI ◽  
Donatella BARRA ◽  
Francesco BOSSA ◽  
C. Borri VOLTATTORNI
Keyword(s):  
Amino Acid ◽  
Primary Structure ◽  
Dopa Decarboxylase ◽  
Pig Kidney

Circular dichroism of polypeptides

1967 ◽  
Vol 297 (1448) ◽  
pp. 163-170 ◽  
Keyword(s):  
Conformational Changes ◽  
Control Mechanisms ◽  
Ordered Structure ◽  
Ordered Structures ◽  
Naturally Occurring ◽  
Synthetic Polypeptides ◽  
Spectroscopic Characteristics ◽  
Physical Attributes ◽  
The Right ◽  
Polypeptide Conformation

The polypeptides, together with the polynucleotides, are polymers which possess the unique property, under the right conditions, of forming ordered structures in dilute isotropic solution. This general attribute is responsible for the precise specificity of structure, and consequently of biochemical function, of the naturally occurring proteins and nucleic acids in their most usual native environment, aqueous solution. It gives rise also to the possibility of extraordinarily delicate biological control mechanisms, based on the induction of conformational changes in the macromolecule by small alterations in the environment. The most versatile methods available for the study of polypeptide conformation in solution are without doubt the spectroscopic ones, and of these the measurement of optical activity is preeminent. The ordered structure of these molecules—and we shall consider here primarily the synthetic homopolyamino acids—makes it possible to regard them essentially as one dimensional unimolecular crystals, and indeed they possess a number of important physical attributes associated with the crystalline state. Thus the collapse of the ordered structure when the environment is changed commonly occurs in a sharp cooperative manner, recalling a crystalline phase transition (melting). More particularly the ordered system of chromophores (peptide groups) gives rise to certain of the spectroscopic characteristics of molecular crystals, and it is these phenomena which provide us with the principal means of studying synthetic polypeptides and proteins in solution. It is evident then that a better understanding of these effects will be of the greatest relevance to the study of conformations and conformational changes in these molecules.

Further experiments on the value of dissolved organic matter as food for Siboglinum fiordicum (Pogonophora)

1979 ◽  
Vol 59 (1) ◽  
pp. 133-148 ◽  
Author(s):  
A. J. Southward ◽  
Eve C. Southward ◽  
T. Brattegard ◽  
T. Bakke
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Organic Matter ◽  
Organic Acids ◽  
Experimental Conditions ◽  
Larval Stages ◽  
Low Concentrations ◽  
Volatile Organic ◽  
Volatile Organic Acids ◽  
Almost All

Adult and larval stages of Siboglinum fiordicum, collected from 32 to 35 m depth, accumulate measurable quantities of amino acids and glucose from low concentrations. The amino acids are absorbed against a considerable gradient. The glucose and the amino acids are metabolized in the tissues and substantial amounts are respired to give carbon dioxide or volatile organic acids. Under the experimental conditions almost all the metabolism follows aerobic pathways.

Volumetric Behavior of 2-Methoxyethanol+1,2-Dimethoxyethane Binary Mixtures

1994 ◽  
Vol 47 (3) ◽  
pp. 415 ◽  
Author(s):  
F Corradini ◽  
A Marchetti ◽  
M Tagliazucchi ◽  
L Tassi
Keyword(s):  
Molar Volume ◽  
Binary Mixtures ◽  
Conformational Changes ◽  
Excess Molar Volume ◽  
Stoichiometric Composition ◽  
Excess Molar Volumes ◽  
The Other ◽  
Experimental Conditions ◽  
Complex Species ◽  
Volumetric Behavior

Thermodynamic interactions in 2-methoxyethanol (component 1)+1,2-dimethoxyethane (component 2) binary mixtures have been studied in terms of the excess molar volume from the densities, measured at 19 temperatures between -10 and 80°C, for nine binary mixtures covering the whole miscibility field expressed by the mole fraction 0 ≤ X1 ≤ 1. Excess molar volumes are discussed in terms of induced conformational changes in each component in the presence of the other. The present findings support a hypothesis about the formation of a solvent-cosolvent complex species which has a well defined 1:1 stoichiometric composition and is thermostable under the experimental conditions.

The chymotryptic phosphopyridoxyl peptide of DOPA decarboxylase from pig kidney

1977 ◽  
Vol 78 (1) ◽  
pp. 177-184 ◽  
Author(s):  
F. Bossa ◽  
F. Martini ◽  
D. Barra ◽  
C.Borri Voltattorni ◽  
A. Minelli ◽  
...  
Keyword(s):  
Dopa Decarboxylase ◽  
Pig Kidney
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