Horse protein

Serum sickness. This occurs when there is an excess of anhgen to antibody, resulting in the formation of soluble complexes. These may circulate and cause systemic reactions or be widely deposited in the kidneys, joints and skin. A rise in temperature, swollen lymph nodes, a generalized urticarial rash and painful swollen joints occur. The rcpeated administration of foreign serum (e.g. antidiphtheria serum or antitetanus serum prepared in horses) can lead to this condition due to antibodies being produced to the horse protein material. 

From Jomvall (84). Except for a few positions not analyzed (empty spaces) and for some peptides ordered by homology, the structure is complete. An insertion, compared to the horse protein, is between positions 111 and 112 in the latter.,... 

Investigations of intramolecular ET In heme proteins have focused on cytochrome c (104 amino acids in the horse protein 12.5 kDa ii° = 0.26 V vs. NHE) see Iron Heme Proteins Electron Transport) (Figure 2). Early... 

Historically, horse immunoglobulins have been of interest because of the use of horse antiserums, such as antitetanus toxin or antidiphtheria toxin, for therapeutic purposes. These are less widely employed now owing to the advent of antibiotics, the development of improved vaccines, and the hazards of serum sickness associated with inoculation of horse proteins into patients. Horse immunoglobulins are less thoroughly characterized, with respect to amino acid sequence, than mouse and human immunoglobulins, in part because equine myeloma proteins are not available. 

Cytochrome c derived from tuna fish reacts slower with the immobilized oxidase compared to cytochrome c derived from horse at the same concentration. This is due to a smaller protein/enzyme dissociation constant for tuna protein compared to horse protein. These data show that electron transfer from tuna cytochrome c to the enzyme is rate limiting even at concentrations of 10 xM and above. 

A sample of the protein, horse heart myoglobin, was dissolved in acidified aqueous acetonitrile (1% formic acid in HjO/CHjCN, 1 1 v/v) at a concentration of 20 pmol/1. This sample was injected into a flow of the same solvent passing at 5 pl/min into the electrospray source to give the mass spectrum of protonated molecular ions [M + nH] shown in (a). The measured ra/z values are given in the table (b), along with the number of protons (charges n) associated with each. The mean relative molecular mass (RMM) is 16,951,09 0.3 Da. Finally, the transformed spectrum, corresponding to the true relative molecular mass, is shown in (c) the observed value is close to that calculated (16,951.4), an error of only 0.002%. 

Most nuts for commercial use are characteri2ed by high oil and protein contents (see Proteins) as well as a low percentage of carbohydrates (qv). However, some varieties, mostly inedible tree nuts such as acorn, horse chestnut, and chufa, contain at least as much sugar and/or starch as protein. The edible water chestnut is also in this category, as is the cashew nut, which contains starch in addition to a rich store of oil. The proximate composition of a number of nuts and of some nut products are given in Table 2 (3). 

ADH Horse liver alcohol dehydrogenase, an enzyme dimer of identical 374 amino acid polypeptide chains. The amino acid composition of ADH is reasonably representative of die norm for water-solnble proteins. 

Both attractive forces and repulsive forces are included in van der Waals interactions. The attractive forces are due primarily to instantaneous dipole-induced dipole interactions that arise because of fluctuations in the electron charge distributions of adjacent nonbonded atoms. Individual van der Waals interactions are weak ones (with stabilization energies of 4.0 to 1.2 kj/mol), but many such interactions occur in a typical protein, and, by sheer force of numbers, they can represent a significant contribution to the stability of a protein. Peter Privalov and George Makhatadze have shown that, for pancreatic ribonuclease A, hen egg white lysozyme, horse heart cytochrome c, and sperm whale myoglobin, van der Waals interactions between tightly packed groups in the interior of the protein are a major contribution to protein stability. 

Homogenates of MetruUum senile, possibly the world s most common large sea anemone, yield extracts that are powerfully hemolytic for washed mammalian erythrocytes (22). The active substance, metridiolysin, is a protein of molecular weight approximately 80,000. In contrast to the sphingomyelin-inhibitable toxins, metridiolysin is an acidic protein having a pi of about 5. It is thermolabile and is inactivat by proteolytic enzymes. The optimal pH for hemolysis is between 5 and 6, and at pH 8 the lysin is inactive. It can be dissociated into two subunits of unequal size. Besides being cytolytic in vitro, metridiolysin is lethal when injected intravenously into mice. As shown in Table IV erythrocytes from the horse or dog are about a hundred times as sensitive to lysis as those from the mouse, and erythrocytes from other animals tested are intermediate in sensitivity. 

Figure 17.8 Catal3ftic zinc center of horse liver alcohol dehydrogenase revealed from an X-ray crystallographic structure (PDB file 20HX) [Al-Karadaghi et al., 1994]. The bound NADH cofactor, a molecule of the inhibitor dimethylsulfoxide (DMSO), and the amino acid residues that coordinate the Zn are shown as sticks shaded according to the elements, and the Zn center is shown as a gray sphere, while the protein is shown in thin gray lines.

Fig. 40. Far-UV CD spectra of /Flactamase from Bacillus cereus (A), horse apomyo-globin (B), and horse ferricytochrome c (C) as a function of HC1 concentration. Protein concentrations were 10 fiM. The numbers refer to the HC1 concentration (mM). The spectra of the native state (A), the A state induced by KC1, pH ss 2), (O) and GdmCl-unfolded state (4-5 M GdmCl, 25 mM phosphate buffer, pH 7.0) ( ) are shown for comparison. From Goto et al (1990a). 1990, with permission of the authors.

Laufberger had tried to obtain the protein from horse liver, but it did not crystallize, and as he described to me when I met him in Prague some years ago, in those days everyone wanted to have protein crystals as a criteria of purity. Although James Sumner had crystallized jack bean urease in 1926, his preparations were somewhat impure, and it was only in the mid-1930s, when John Northrop and Moses Kubnitz showed that there is a direct correlation between the enzymatic activities of crystalline pepsin, trypsin and chymotrypsin that the protein nature of enzymes was generally accepted. 

Ferritins have been found in a wide range of species, and sequence data - some, as in the first ever sequence of horse spleen apoferritin (Heusterspreute and Crichton, 1981) determined by direct methods, but many now by DNa sequencing 1, have been deposited for more than 70 ferritins. They vary in length from 154-185 residues per subunit. Some ferritins have N-terminal extensions which lie on the outside of the assembled shell and target the ferritin to a specific destination such as plastids in plants and yolk sac in snails (Andrews etah, 1992 Lobreaux etah, 1992). For example, pea ferritin is synthesized with an N-terminal extension of 75 residues, which is missing from the mature protein. The first part of this extension is a chloroplast-targetting sequence of 47 residues, which is lost on entry into the plastid. The second part, an extension peptide, is lost prior to assembly of the... 

Daidone, I., Amadei, A., Roccatano, D., Nola, A. D., Molecular dynamics simulation of protein folding by essential dynamics sampling folding landscape of horse heart cytochrome c, Biophys. J. 2003, 85, 2865-2871... 

The improvement of its activity and stability has been approach by the use of GE tools (see Refs. [398] and [399], respectively). A process drawback is the fact that the oxidation of hydrophobic compounds in an organic solvent becomes limited by substrate partition between the active site of the enzyme and the bulk solvent [398], To provide the biocatalyst soluble with a hydrophobic active site access, keeping its solubility in organic solvents, a double chemical modification on horse heart cytochrome c has been performed [400,401], First, to increase the active-site hydrophobicity, a methyl esterification on the heme propionates was performed. Then, polyethylene glycol (PEG) was used for a surface modification of the protein, yielding a protein-polymer conjugates that are soluble in organic solvents. 

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