Protein Molecules: Evolution’s Design for Kinematic Machines

2013 ◽  
pp. 217-244 ◽  
Author(s):  
Kazem Kazerounian ◽  
Horea T. Ilieş
Keyword(s):  
Protein Molecules

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.

Effect of the membrane potential on the performance of ultrafiltration membranes

1986 ◽  
Vol 51 (3) ◽  
pp. 539-544 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Jaromír Lukáš ◽  
Jiří Vacík ◽  
Volker Gröbe
Keyword(s):  
Membrane Potential ◽  
Concentration Polarization ◽  
Ultrafiltration Membranes ◽  
Membrane Cleaning ◽  
Gel Layer ◽  
Charged Membrane ◽  
Protein Molecules ◽  
Polysulfone Membranes ◽  
Pressure Driven

In the pressure driven process the performance of membranes for ultrafiltration can be changed by incorporating charged groups into the membranes. sulfonation of polysulfone membranes the membrane potential is varied. On interaction of the negatively charged membrane with positively or negatively charged protein molecules the formation of a concentration polarization gel layer proceeds at different rate. Thus, the performance of the membrane can be controlled by the membrane potential. The dependence of the performance on the potential is discussed and procedures for membrane cleaning are suggested.

High-Speed Lens-Free Holographic Sensing of Protein Molecules Using Quantitative Agglutination Assays

ACS Sensors ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 1208-1217
Author(s):  
Zhen Xiong ◽  
Colin J. Potter ◽  
Euan McLeod
Keyword(s):  
High Speed ◽  
Protein Molecules

Coagulation of organic pollutants by Moringa oleifera protein molecules: In silico approach

2021 ◽  
Author(s):  
Victoria Teniola Adeleke ◽  
Adebayo A Adeniyi ◽  
David Lokhat
Keyword(s):  
Wastewater Treatment ◽  
Organic Pollutants ◽  
In Silico ◽  
Moringa Oleifera ◽  
Seed Protein ◽  
Clean Water ◽  
Protein Extract ◽  
Natural Coagulant ◽  
Global Challenge ◽  
Protein Molecules

Availability of clean water for various activities is a global challenge. Moringa oleifera (MO) seed protein extract has been identified as a natural coagulant for wastewater treatment. The mechanistic understanding...

scholarly journals Structure and Location of Protein Sites Binding Self-Associated Congo Red Molecules with Intercalated Drugs as Compact Ligands—Theoretical Studies

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 501
Author(s):  
Ptak-Kaczor Magdalena ◽  
Kwiecińska Klaudia ◽  
Korchowiec Jacek ◽  
Chłopaś Katarzyna ◽  
Banach Mateusz ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Light Chain ◽  
Congo Red ◽  
Theoretical Studies ◽  
Mathematical Tool ◽  
Supramolecular Systems ◽  
Micellar Structure ◽  
Protein Molecules ◽  
Toxic Drugs ◽  
Independent Property

In the search for new carriers capable of transporting toxic drugs to a target, particular attention has been devoted to supramolecular systems with a ribbon-like micellar structure of which Congo red is an example. A special promise of the possible use of such systems for directing drugs to a target emerges from their particular affinity to immune complexes and as an independent property, binding many organic compounds including drugs by intercalation. Serum albumin also appeared able to bind micellar particles of such systems. It may protect them against dilution in transport. The mathematical tool, which relies on analysis of the distribution of polarity and hydrophobicity in protein molecules (fuzzy oil drop model), has been used to find the location of binding area in albumin as well as anchorage site for Congo red in heated IgG light chain used as a model presenting immunoglobulin-like structures. Results confirm the suggested formerly binding site of Congo red in V domain of IgG light chain and indicated the cleft between pseudo-symmetric domains of albumin as the area of attachment for the dye.

scholarly journals On the Formation of Covalent Linkages between Two Protein Molecules

1961 ◽  
Vol 236 (9) ◽  
pp. 2477-2485
Author(s):  
Anita F. Schick ◽  
S.J. Singer
Keyword(s):  
Protein Molecules

scholarly journals ‘Tanned’ gelatin spheres and granules for exclusion chromatography

1968 ◽  
Vol 108 (4) ◽  
pp. 641-646 ◽  
Author(s):  
A. Polson ◽  
W. Katz
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
High Molecular Weight ◽  
Weight Fraction ◽  
High Flow ◽  
High Molecular Weight Fraction ◽  
Flow Rates ◽  
Protein Molecules ◽  
Exclusion Chromatography

1. The preparation of tanned gelatin spheres and granules from high-molecular-weight gelatin is described. This material is comparatively hard, giving high flow rates, is insoluble in water at temperatures between 0° and 100° and is resistant to digestion by trypsin and chymotrypsin. The high-molecular-weight fraction of gelatin was prepared by precipitation with polyethylene glycol, and the spheres and granules prepared from this fraction were hardened and insolubilized by tanning with either formalin or chromium salts or both. 2. The spheres and granules were used successfully for the separation of protein molecules and other protein-aceous materials ranging in molecular weight from 200 to greater than 6000000. This gel exclusion material has several properties superior to those of other products used for similar purposes. Further, it was noticed that the porosity of the spheres differed considerably from that of the granules.

Proton magnetic relaxation of water sorbed by methaemoglobin crystals

1973 ◽  
Vol 331 (1587) ◽  
pp. 457-468 ◽  
Keyword(s):  
Relaxation Rate ◽  
Relaxation Times ◽  
Transverse Relaxation Rate ◽  
Ferric Ions ◽  
Transverse Relaxation ◽  
Water Binding ◽  
Adsorption Sites ◽  
Protein Molecules ◽  
Proton Magnetic Relaxation ◽  
Limiting Value

P. m. r. relaxation times ( T 1 and T 2 ) have been measured as a function of regain and temperature for water sorbed by lyophilized methaemoglobin. The purpose of the work was to gain information regarding the nature and extent of water binding by the protein molecules. The T 1 results are interpreted in terms of an exchange between the sixth ligand position of the Fe (III) and other adsorption sites on the protein. At high temperatures the relaxation rate at a given regain reaches a limiting value which allows the fraction of ferric ions hydrated to be calculated. Above 16% regain all the Fe (III) is hydrated. At 21 and 35% regains a maximum appears in the relaxation rate at about -46 °C indicating a contribution from a more mobile phase which produces a T 1 minimum at that temperature. The T 2 data are consistent with a model in which the main contribution to the transverse relaxation rate comes from a tightly bound fraction of the water with ω 0 Ƭ c ≫1. The temperature dependence of T 2 exhibits three different regions: ( a ) a low temperature region where lg T 2 ∝ T -1 ; ( b ) an intermediate region with a steeper increase of T 2 with temperature; and ( c ) a high temperature where T 2 levels off.

scholarly journals NMR Protein Structure Calculation and Sphere Intersections

2020 ◽  
Vol 8 (1) ◽  
pp. 89-101
Author(s):  
Carlile Lavor ◽  
Rafael Alves ◽  
Michael Souza ◽  
Luis Aragón José
Keyword(s):  
Protein Structures ◽  
Structure Calculation ◽  
Bp Algorithm ◽  
Main Step ◽  
Combinatorial Method ◽  
Nmr Data ◽  
Sampling Process ◽  
Protein Molecules ◽  
Protein Structure Calculation ◽  
Branch And Prune

AbstractNuclear Magnetic Resonance (NMR) experiments can be used to calculate 3D protein structures and geometric properties of protein molecules allow us to solve the problem iteratively using a combinatorial method, called Branch-and-Prune (BP). The main step of BP algorithm is to intersect three spheres centered at the positions for atoms i − 3, i − 2, i − 1, with radii given by the atomic distances di−3,i, di−2,i, di−1,i, respectively, to obtain the position for atom i. Because of uncertainty in NMR data, some of the distances di−3,i should be represented as interval distances [{\underline{d}_{i - 3,i}},{\bar d_{i - 3,i}}], where {\underline{d}_{i - 3,i}} \le {d_{i - 3,i}} \le {\bar d_{i - 3,i}}. In the literature, an extension of the BP algorithm was proposed to deal with interval distances, where the idea is to sample values from [{\underline{d}_{i - 3,i}},{\bar d_{i - 3,i}}]. We present a new method, based on conformal geometric algebra, to reduce the size of [{\underline{d}_{i - 3,i}},{\bar d_{i - 3,i}}], before the sampling process. We also compare it with another approach proposed in the literature.

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