Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An extracellular protease of Serratia marcescens produced during growth on skim milk medium was isolated by ethanol precipitation. The protease was purified by salt fractionation, DEAE-cellulose ion exchange chromatography and gel filtration chromatography on Agarose P-100. It has a broad optimum from pH 6.0 to 9.0 and a temperature optimum of 45 degrees C for proteolytic activity on casein. It was classified as a metallo-protease by virtue of its inactivation by metal-ion chelators and reactivation by ferrous ions. Proteolytic activity was not affected by diiso-propylfluorophosphate, p-chloromercuribenzoate and dithiothreitol.
Mol Cell Biochem 1976 Nov 30
PMID:The extracellular metalloprotease of Serratia marcescens: I. Purification and characterization. 1 65

1. Angiotensin I-generating activity of rat brain extract was separated into two components by affinity chromatography on a casein-Sepharose gel column. 2. The component without affinity to the gel was identified as true renin on the basis of its sensitivity to anti-renin antibody and the lack of protease activity. 3. The second renin-like component with affinity to the gel was a protease insensitive to the anti-renin antibody. Its renin-like activity examined with sheep substrate was pronounced compared with the rate of angiotensin I generation from the rat substrate. 4. It was concluded that rat brain contains true renin, which can be detected by the use of rat substrate but can be masked when examined with sheep substrate.
Clin Sci Mol Med Suppl 1978 Dec
PMID:Definitive evidence for renin in rat brain by affinity chromatographic separation from protease. 3 1

The protein kinase activities of a transplantable, insulin-producing hamster islet cell tumor were characterized using gel filtration, sucrose density gradient centrifugation and acrylamide gel electrophoresis. The post-microsomal supernatant fluid contains 70-80% of the protein kinase activity present in crude homogenates. A cAMP-dependent protein kinase, PK I (Mr 170,000), represents 25% of the soluble protein kinase activity assayed with protamine as substrate. It dissociates in the presence of cAMP into a cAMP-binding protein, R2 (Mr 90,000) and a catalytic subunit C (Mr 33,000). The dissociation induced by cAMP seems to be facilitated by the addition of Mg2+ and ATP. The regulatory subunit, R2, changes its gel filtration pattern in the presence of 0.5 M NaCl suggesting dissociation into a smaller subunit, R1 (Mr 44,000). By analogy with purified beef heart protein kinase (Erlichman et al., 1973) and skeletal muscle protein kinase, PK I. The presence in crude homogenates of a free cAMP-binding protein indistinguishable from the R2 derived by dissociation of PK I, suggests that PK I is partially dissociated in vivo. A cAMP-independent (casein) kinase (Mr 210,000) elutes with PK I on columns of Sepharose 6B. Another cAMP-independent protein kinase, PK II (Mr 88,000), is the predominatn form of soluble protein kinase accounting for approximately 75% of the soluble protein kinase activity detected using protaimine as substrate. This cAMP-independent protein kinase changes its gel filtration pattern in the presence of 0.5 M NaCl giving rise to a form which appears to have the same Mr (33,000) as the catalytic subunit of PK I. Studies comparing the catalytic subunit C of PK I with PK II and its salt-induced smaller molecular form demonstrate facile association of C with the cAMP-binding protein of purified bovine heart protein kinase to yield a hybrid holoenzyme, whereas PK II and its smaller form fail to recombine in this fashion. The 33,000 dalton forms derived from PK I (by cAMP) and PK II (by salt) also show different substrate specificities. It would appear, therefore, that pK II is a cAMP-independent protein kinase unrelated to PK I.
Mol Cell Endocrinol 1976 Feb
PMID:Characterization of the protein kinases in a transplantable islet cell tumor of the Syrian hamster. 17 65

Thyroxine control of cAMP-independent histone and casein phosphokinase activities was studied in thyroidectomized rats treated with thyroxine. All activities were evaluated in the presence of a thermostable inhibitor of cAMP-dependent enzymes. Cytosol enzymes can be resolved by sucrose gradient ultracentrifugation into three peaks of histone kinase activity (3.2S, 5S and 7.2S) and two peaks of casein kinases (3.6S and 7.1S). Neither thyroidectomy nor subsequent treatment of operated animals with thyroxine modifies the total histone kinase activity estimated, either in total cytosol or after its fractionation by the sucrose gradient ultracentrifugation. The activity ratios of different peaks were, however, changed. Casein kinase activity was significantly decreased after thyroidectomy (about 50%). Subsequent treatment with thyroxine restored this activity to its initial value. Sucrose gradient ultracentrifugation analysis showed that thyroxine action on the casein kinase activity is very specific. Only molecules that sediment in the 9S region were significantly stimulated by the hormone. Cortisol action on the casein kinase activity was studied in adrenalectomized animals treated with hormone for 24 h. Cortisol decreases the total casein kinase activity by about 30%. Sucrose gradient ultracentrifugation analysis showed that the population of molecules sedimenting at about 9S was the most sensitive to cortisol. The above data show that both thyroxine and cortisol control, in a selective way, the activities of cAMP-independent protein kinases. The same kinase molecules can be under double control by two different hormones that have opposite effects.
Mol Cell Endocrinol 1978 Dec
PMID:Hormonal regulation of cAMP-independent protein phosphokinase activities: thyroxine and cortisol control of enzymes from rat liver cytosol. 21 94

Histone kinase activity was purified from human polymorphonuclear leukocytes by ammonium sulphate precipitation of a 180 000 x g supernatant, followed by DEAE-cellulose chromatography and gelfiltration. On DEAE-cellulose cAMP dependent kinase activity eluted in two peaks, I and III, at 1.2 mmho and 6.5 mmho, respectively. Catalytic subunit (C) from both peaks had Mr 33 000, 3.0S. Regulatory subunit (R) from peak I and III both had Mr 33 000 upon gelfiltration, but sedimented at 2.8--3.0S and 3.0--3.2S, respectively. R2 and R4 subunits were identified. The R-C dimer from peak I and III sedimented at 4.8S and (4.8)--5.1S, respectively. The holoenzyme from peak I had Mr 165 000, 6.7S, which suggest a R2C2 structure, while that of peak III sedimented at 6.7S, but eluted at Mr 330 000 (2R2C2) by gelfiltration. The Kmapp for peak I and III enzymes were, respectively: histone IIA 0.5 mg/ml (both forms), ATP 18 microM and 23 microM, and cAMP 5 X 10(-8) M and 6.3 x 10(-8) M. Both enzymes had pH optimum 6.7--6.9 and were equally sensitive to Ca2+, temperature and protein kinase inhibitor. The substrate specificity was histone VS greater than histone IIA = histone VIS greater than casein greater than phosvitin. Peak I enzyme, but not peak III enzyme, was dissociated by histone and high ionic strength and reassociation of R and C subunits were facilitated by ATP-Mg. It is concluded that peak I and III enzymes represent type I and II cAMP dependent protein kinases, respectively. Type I comprises 20--30% of cAMP dependent protein kinase activity and is absent from the 180 000 x g supernatant of gently disrupted cells. Purified catalytic subunit had Kmapp (ATP) 20 microM with rabbit muscle glycogen synthease I as substrates. Synthase I from rabbit muscle and human leukocytes were phosphorylated by catalytic subunit to synthase D (ratio of independence less than 0.07). cAMP independent histone kinase activity eluted in one peak (Peak II) at3 mmho. The enzymatic activity sedimented at 3.4S and eluted from gelfiltration with Mr 78 000. Kmapp for ATP was 78 microM and for histone IIA 0.5 mg/ml. The enzyme was sensitive to temperature, but less sensitive than cAMP dependent protein kinase to Ca2+, and insensitive to protein kinase inhibitor. The substrate specificity was histone IIA greater than histone VS = histone VIS, while casein and phosvitin were poor substrates. Glycogen synthase I was not phosphorylated. The cAMP independent histone kinase activity comprised 15% of the total histone kinase activity in a crude homogenate of leukocytes. Its physiological substrate is unknown.
Mol Cell Biochem 1979 Jul 15
PMID:Purification and properies of cAMP dependent and independent histone kinases from human leukocytes. 22 66

The binding to neutrophil leukoyctes of human serum albumin (HSA), which is chemokinetic for leukocytes, i.e. influences their rate of locomotion, and of alkali-denatured HSA, which is chemotactic for leukocytes, i.e. influences their direction of locomotion, was studied. Native serum albumin showed low affinity binding to the neutrophil surface. Denatured serum albumin showed saturable binding with a Ka of approximately 1-(6) litres per mole to about 10(6) binding sites per cell. Another protein chemotactic factor, alpha5-casein, gave similar binding. These results exclude that chemotactic reactions to denatured proteins are mediated in a completely non-specific manner and suggest the presence on the cell of a restricted number of defined recognition sites. Binding was reduced following treatment of the cells with either of two lipid-specific bacterial toxins, perfringolysin, the theta-toxin of Clostridium perfringens, an oxygen-labile cholesterol-specific toxin, and Staphylococcus aureus Sphingomyelinase C. Both have previously been shown to reduce chemotactic reactions and both were used at doses which did not reduce cell viability. These results suggest an important, and possiblly direct, role for membrane lipid in the binding sites for chemotactic factors. Visual analysis of the behaviour of perfringolysin-treated neutrophils showed that these cells were still capable of chemotactic locomotion. The cells appeared to be less efficient than normal in detecting chemotactic gradients only when at a distance from the gradient source, a finding which is consistent with reduced binding of the chemotactic factor to the cell surface.
Mol Cell Biochem 1978 Jun 15
PMID:Binding of protein chemotactic factors to the surfaces of neutrophil leukocytes and its modification with lipid-specific bacterial toxins. 67 3

The proteolytic activity of the extracellular protease of Serratia marcescens was compared with that of trypsin on N, N-dimethyl casein. The peptides produced from exhaustive hydrolysis of alpha casein by the protease and by trypsin were of similar size as measured by gel filtration on P-10 Agarose. We conclude that the protease of S. marcescens in an endopeptidase with trypsin-like activity on proteins, producing oligopeptides. End group analysis of the peptides formed by the S. marcescens protease suggests that the protease has a unique substrate specificity, hydrolyzing only a peptide bond whose carboxyl group is donated by proline. The protease was inactive on the synthetic peptides with proline donating the carboxyl group, but hydrolyzed various types of natural proteins. Its narrow and novel substrate specificity makes this enzyme a potential tool for the determination of the primary structure of proteins.
Mol Cell Biochem 1976 Dec 10
PMID:The extracellular metalloprotease of Serratia marcescens. 2. Comparison with trypsin and substrate specificity. 79 98

A protein kinase specific for casein and acidic ribosomal proteins was isolated and partly characterized. It was found that the enzyme utilizes GTP and ATP as phosphoryl donors. Its affinity for ATP was considerably higher than for GTP with the km values of 7.6 X 10(-6)M and 5.5 X 10(-5)M, respectively. Two-dimensional acrylamide gel electrophoresis revealed the phosphorylation of the same ribosomal proteins with either of the [gamma-32P] nucleotides used. It was also shown that one acidic protein (S1 or S2) of 40 S and two acidic proteins (L2 and L3) of 60 S ribosomal subunits were predominantly phosphorylated in vitro. The phosphorylated proteins: L2 and L3 seem to correspond to the proteins of L7 and L12 of E. coli ribosomes. The isolated kinase phosphorylated several basic ribosomal proteins though to a lower extent than the acidic ones.
Mol Biol Rep 1976 Nov
PMID:Ribosomal protein as substrate for a GTP-dependent protein kinase from yeast. 79 85

1. The characteristics of absorption of individual amino acids from amino acid mixtures simulating casein and from enzymic hydrolysates of casein containing oligopeptides as well as free amino acids are known to be different. The differences, which are attributable to mucosal uptake of small peptides, involve more rapid absorption from the enzymic hydrolysates of certain amino acids which are relatively slowly absorbed from the amino acid mixtures. This could lead to more effective utilization of amino acids from the enzymic hydrolysates than from the amino acid mixtures. 2. To obtain further information bearing on this hypothesis, we have used a recently developed technique for portal cannulation in the guinea pig to make a preliminary investigation of amino acid concentrations in the portal venous plasma at intervals after the infusion into the duodenum of equivalent amounts of (a) an amino acid mixture simulating casein and (b) a partial enzymic (papain followed by kidney peptidases) hydrolysate of casein, the two preparations being infused in separate experiments. 3. For some amino acids, such as leucine, isoleucine, valine, phenylalanine and lysine, the curves after the enzymic hydrolysate were fairly similar to the corresponding curves after the amino acid mixture, though usually slightly lower. With other amino acids, the curves after the enzymic hydrolysate were very much lower than the corresponding curves after the amino acid mixture. With serine, glutamine, proline and glycine this discrepancy was particularly great. 4. The results cannot yet be fully explained, but their main features are explicable by the hypothesis that the lower amino acid concentrations in portal plasma after the enzymic hydrolysate are the result of entry of amino acids into the portal blood in peptide form, in which they would not be detectable by the analytical technique employed, and possibly also of more rapid clearance of amino acids from the blood during absorption of this preparation.
Clin Sci Mol Med 1977 Mar
PMID:Amino acid concentrations in portal venous plasma during absorption from the small intestine of the guinea pig of an amino acid mixture simulating casein and a partial enzymic hydrolysate of casein. 84 57

1. A jejunal perfusion technique has been used in normal volunteer subjects to study jejunal absorption of amino acid residues from a partial enzymic hydrolysate of casein in which about 50% of the amino acids existed as small peptides, and also from an equivalent mixture of free amino acids. 2. The effect of a high concentration of the dipeptide glycylglycine on the absorption of amino acid residues from these preparations was studied to quantify the importance of mucosal uptake of intact peptides during absorption of the partial hydrolysate of casein. 3. The results were unexpected. Glycylglycine significantly inhibited absorption of several amino acid residues (aspartic acid + asparagine, serine, glutamic acid + glutamine, proline, alanine, phenylalanine, threonine and isoleucine) from the free amino acid mixture, whereas it significantly inhibited the absorption of only two (serine, glutamin acid + glutamine) from the peptide-containing partial casein hydrolysate. 4. The effect of glycylglycine on absorption of amino acids from the mixture of free amino acids was apparently due to inhibition of amino acid uptake by free glycine liberated from the dipeptide during perfusion. The reason for the failure of glycylglycine to cause extensive inhibition of absorption from the partial hydrolysate is not clear. It may be due to glycylglycine being only a weak inhibitor of peptide uptake, but the possibility that some peptides are taken up by a system unavailable to glycylglycine has to be considered.
Clin Sci Mol Med 1977 Jul
PMID:Effect of glycylglycine on absorption from human jejunum of an amino acid mixture simulating casein and a partial enzymic hydrolysate of casein containing small peptides. 87 18


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