Cysteine spleen

Fig. 14. Initial interval of cleavage of HPMA copolymer based polymeric substrates by lysosomal cysteine proteinase cathepsin B (isolated from bovine spleen). Only the cleavage of the bond between the distal amino acid residue and p-nitroaniline was monitored. Conditions of cleavage [Cathepsin B] = 1.9 x 10 7 M [NAp] = 1.2 x 1(T3 M [EDTA] = 1 x 10 3 M [Cys] = 2.5 x 10 2 M 0.1 M phosphate buffer pH = 6.0 40 °C. Data from [249]...

Figure 3.5. Reversible and irreversible inhibition of a-adren-ergic receptors in the spleen, a Contractile tension developed by spleen slices in response to norepinephrine, in the presence of tolazoline and phenoxybenzamine. b Stmctures of norepinephrine, tolazoline, and phenoxybenzamine. c Reaction of phenoxybenzamine with the a-adrenergic receptor. The initial formation of the aziridine ring occurs in solution. The aziridine then reacts with a nucleophilic amino acid side chain (most probably a cysteine) in the binding site of the receptor.

Elastase activity is not a universal property of proteolytic sulfhydryl-activated enzymes. There are abundant reports in the literature describing the disappearance of elastic fibers in vivo preceding the repair of damaged tissues, but there is no evidence as to how this is brought about. The tissue cathepsins, most of which are SH-activated, have received little systematic study, but Thomas and Partridge (1960) reported that cathepsins extracted from kidney and spleen by the method of De La Haba et al. (1955) did not digest elastin either in the presence or the absence of cysteine. 

Abstract The diet of industrialised countries is usually rich in amino acids, which are partly used as a source of calories. However, metabolic alterations are observed in diseased patients and a preferential retention of Sulphurated Amino Acids (SAA) occurs during the inflammatory response. It has been demonstrated in an acute sepsis phase model in rats that the metabolism of L-Cysteine (Cys) is modified. Glutathione (GSH) concentration is greater in the liver, kidneys and other organs and Cys incorporation into proteins is higher in the spleen and lungs. In the plasma Acute Phase Proteins are released while Albumin is decreased. The pro-inflammatory cytokines such as Interleukin-1, lnterleukin-6 and TNF-a are the main initiators altering protein and amino acid metabolism. 

The HCC subgroup of CC chemokines also exhibits proinflammatory functions. HCC-1 actually has 46% homology with MIP-1 a and MIP-1/3, but it is constitutively expressed in normal spleen, liver, gastrointestinal tract, skeletal and heart muscle, and bone marrow and is present at 1-10 nM concentrations in plasma (Schulz-Knappe et al., 1996). Although HCC-1 utilizes CCRl, it is a weak activator of calcium flux only for monocytes and induces CD34+ myeloid progenitor cell proliferation (Table 6). In contrast, HCC-2 (or leukotactin 1) expression is restricted to the gut and liver (Pardigol et al., 1998). It is a CC chemokine with six cysteines and a putative third disulfide bond. HCC-2 utilizes CCRl and is functionally similar to MIP-1 a with potent chemotactic effects on monocytes and... 

The in vivo mechanism of 35S-taurine formation from 35S-cysteine in the rat has been studied by Awapara and Wingo148. Ten minutes after injection, large amounts of 35S cysteine and traces of sulphate-35S were found only in the liver. After 20 minutes small amounts of 2-aminoethanesulphinic-3 5 S acid were also found (equation 81). Taurine began to appear in the liver 30 minutes after the injection. Two hours after administration, analyses for [35S]taurine, alanine, [35S]cysteic acid and 2-aminoethanesulphinic acid were carried out in liver, kidney, heart and spleen of the rats. [3 5S]Cysteic acid had been detected only when large amounts of 35S-labelled cysteine were injected. It has been suggested that the degradation of [35S]cysteine in vivo proceeds in rats according to equation 81. Formation of 2-aminoethanesulphinic acid and its oxidation to taurine is a preferred pathway. Much less [35S]sulphate than 2-aminoethanesulphinic-35S acid and taurine-35S had been found one hour after incorporation of 35S-labelled cysteine. 

The addition of NifS to horse spleen ferritin does not sustain iron release at a high rate after an initial burst (Cassanelli and Moulis 2001). This increase in soluble iron can be attributed to endogenous compounds able to expel iron from ferritin. Addition of the NifS substrate, L-cysteine, increases the rate. 

Pirie (95) used slices of liver and kidneys of rats and found that these tissues oxidize the cysteine sulfur to sulfate. Having thus shown the enzymic character of this oxidation, he attributed it to the existence of a cysteine oxidase. This substance is lacking in blood, testicles, spleen, heart, and lung. The same enzymic reaction was observed by Medes (85) with a filtrate of ground rat liver in a solution buffered with carbonate. The enzymic system under observation, suspended either in a carbonate buffer solution, or in a dilute neutral salt solution, is easily adsorbed on permutite, but its subsequent elution has not been accomplished to date. Otherwise, the same enzymic system is precipitated upon addition of magnesium or sodium sulfate, but it then loses all its activity. 

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