Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two major proteins, termed proteins A and B, and one minor species, termed protein C, have been purified to homogeneity from dilute acid extracts of dormant spores of Bacillus megaterium. These three species comprise approximately 80% of the protein in the dilute acid extracts and account for 60 to 75% of the protein degraded during spore germination. All three proteins have low molecular weights (7,000 to 10,000), high isoelectric points (greater than 9.8), alanine as the NH2-terminal amino acid, are more hydrophilic than most proteins, and all lack cysteine, cystine, and tryptophan. In addition all three proteins are extremely sensitive to a wide variety of proteolytic enzymes, much more so than "average" proteins such as serum albumin, lysozyme, and hemoglobin. These proteins also bind to both purified DNA and to a nuclear body from dormant spores. Although this binding gives little or no protection to proteins A and B from proteolysis, it does result in elevation of the melting temperature of the DNA by as much as 20degrees.
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PMID:Purification and properties of some unique low molecular weight basic proteins degraded during germination of Bacillus megaterium spores. 80 43

To investigate the possibility that a hypercoagulable state develops during autologous bone marrow transplantation (BMT), we measured levels of circulating natural anticoagulants and fibrinolytic proteins before and weekly during the hospital course of 18 patients undergoing autologous BMT for Hodgkin's and non-Hodgkin's lymphoma. Patients received either weekly (standard dose group) or daily (high dose group) vitamin K supplements with their total parenteral nutrition. By day 14 there had been a significant drop in protein C activity (mean of 95% of normal to 52%), protein C antigen (mean of 105% of normal to 70%), and antithrombin 3 activity (111% of normal to 83%), and an increase in fibrinogen (471-621 mg/dl) and tissue plasminogen activator (6.9-13.8 ng/ml). No changes were seen in free or total protein S, plasminogen activator inhibitor, prothrombin time or partial thromboplastin time. The decreases in protein C and antithrombin 3 persisted through day 28 after transplantation. The drop in protein C correlated strongly with decrease in serum albumin, suggesting impaired synthesis of these proteins by the liver. No differences were seen in any of these parameters between the standard and high dose groups. Deficiencies in anticoagulant proteins antithrombin 3 and protein C and a rise in fibrinogen without a concomitant improvement in fibrinolytic variables create a potentially hypercoagulable state which may contribute to the thrombotic complications of autologous BMT.
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PMID:High frequency of antithrombin 3 and protein C deficiency following autologous bone marrow transplantation for lymphoma. 179 Apr 30

Effect of corticosteroids (steroids) on some hemostatic parameters was serially studied in 23 children with minimal change nephrotic syndrome (MCNS). Increased platelet count, erythrocyte sedimentation rate (ESR), cholesterol, fibrinogen, fibrin(ogen) degradation products (FDP), alpha 2-macroglobulin (alpha 2M), alpha 2-antiplasmin (alpha 2AP) and protein C, and reduced antithrombin III (ATIII) and plasminogen (Plg) were noted in relapse before steroid therapy began. With institution of oral prednisolone, FDP started to fall, and platelet count, cholesterol, alpha 2M, ATIII, Plg, alpha 2AP and protein C started to increase despite unchanged nephrotic state from that before the therapy. In remission induced by prednisolone, platelet count, cholesterol, alpha 2M, ATIII, Plg, alpha 2AP and protein C were still increased, but normalized off therapy. ESR, fibrinogen, FDP, alpha 2M and protein C correlated inversely with serum albumin and directly with cholesterol and urine protein excretion. In contrast, ATIII and Plg correlated directly with serum albumin and inversely with cholesterol and urine protein excretion. A direct correlation was only noted between alpha 2AP and the dose of prednisolone. The data indicate that steroids appear to be a thrombogenic factor by accerelating thrombocytosis and hyperlipidemia, and by reducing plasma fibrinolysis in children with MCNS.
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PMID:Effect of corticosteroids on some hemostatic parameters in children with minimal change nephrotic syndrome. 207 95

We have shown that a cationized form of bovine serum albumin (BSA) produced by substituting anionic side chain carboxylic groups with aminoethylamide groups possesses unique immunologic properties. The two forms of antigen, native (nBSA) and cationized (cBSA), cross-react at the level of the B cell, as evidenced by the ability of antibody raised against one form to react with the other and by inhibition assays using ELISA. T cell cross-reactivity was also observed in proliferation assays, but the amount of cBSA required for stimulation was 500 times less than the amount of native protein needed. In vivo, cBSA produced responses which, at their optimal levels, were at least double the response to nBSA and which showed a different kinetic pattern, peaking later and lasting longer than the response to the native molecule. Moreover, antibodies were produced in response to administration of cBSA but not nBSA when given i.v. in saline, without an adjuvant. Although a mechanism for these phenomena is not yet clear, we speculate that the cBSA may have a greater affinity for antigen-presenting cells or for the T cell receptor, or that the altered structure may enhance recognition of the molecule by APC and/or helper T cells.
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PMID:Cationization of protein antigens. I. Alteration of immunogenic properties. 243 31

The cause of the thrombotic tendency in nephrotic patients is unknown. Recent reports of thrombotic complications in patients with deficiencies of protein C or protein S (natural inhibitors of coagulation) have raised the possibility that decreased levels of these proteins may play a role in the hypercoagulable state of nephrotic patients. We measured the levels of protein C, total protein S, and free protein S antigens in 42 patients (21 nephrotic and 21 non-nephrotic) with one of four types of glomerular pathology: diabetic nephropathy (DM), focal glomerular sclerosis (FGS), membranous glomerulonephritis (MGN), and chronic renal failure due to hypertension (CRF). Protein C and total protein S antigen levels were significantly higher in FGS and MGN than they were in DM or CRF. Free protein S levels were lower in DM than they were in MGN. Protein C, total protein S, and free protein S levels did not significantly correlate with either serum albumin or degree of proteinuria. The mean levels of the three proteins did not differ between nephrotic and non-nephrotic patients. Free protein S and protein C were, however, significantly correlated (P less than .005 and P less than .002, respectively) with the type of glomerular pathology, independent of differences in age, sex, serum albumin, or degree of proteinuria. These data suggest that abnormalities of free protein S and protein C are related to the nature of the underlying renal disease, rather than to the degree of proteinuria.
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PMID:Protein S and C antigen levels in proteinuric patients: dependence on type of glomerular pathology. 252 34

The protein C-protein S natural anticoagulant system was evaluated in 32 patients with proteinuria, 11 without nephrotic syndrome (NS) and 21 with NS of different grade. Antithrombin III (AT III), factors II, VII, X were also measured in the same groups of patients. In addition to plasma levels of these proteins, urinary loss of protein C was evaluated in concentrated urine specimens from 17 of the 21 patients with NS. The protein C antigen level was found to be normal or high in NS, but the difference between the control group and nephrotic patients was statistically significant only in severe NS. For all proteinuric patients, the plasma concentration of protein C correlated positively with the degree of proteinuria, cholesterol level, triglyceride level, and correlated inversely with serum albumin concentration; 17/17 patients with NS exhibited urinary loss of protein C and the degree of protein C excretion correlated positively with the degree of proteinuria. Plasma protein S antigen was measured in only 11 patients with NS and was found to be significatively increased, with a negative correlation with serum albumin concentration. AT III did not differ between the control group and the proteinuric patients with or without NS. Factors II and X were in the normal range for all patients. Factor VII was increased even in mild NS. Thus, the plasma levels of protein C and protein S antigens were normal or increased in patients with NS and this is probably related to an increased liver synthesis rate of these proteins, which is secondary to proteinuria.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Study of the protein C-protein S system in glomerulopathies and nephrotic syndrome]. 295 50

Seventy-four patients with beta-thalassemia major were studied to test the hypothesis that a deficiency of protein C (PC) and antithrombin III (AT III), both antithrombotic proteins, could contribute to the pathogenesis of CNS thromboembolic lesions. In 70 patients, PC levels were found to be significantly lower than normal, whereas AT III activity was found to be lower only in 41 patients. The lowest values of PC and AT III were found in older splenectomized patients, a low PC value only was found in chronic hepatitis patients. Prothrombin time and fibrinogen were found to be particularly abnormal in patients with chronic hepatitis and without spleen. A relatively poor correlation was observed between PC and AT III (p less than 0.02). PC correlated with age (p less than 0.001), transfusional iron (p less than 0.001) and ferritin (p less than 0.001). It also correlated with serum albumin (p less than 0.001), prothrombin time (p less than 0.001) and fibrinogen (p less than 0.02) and with serum transaminases (GPT) (p less than 0.001). The same indexes correlated less significantly with AT III activity. Nevertheless, only 2 of our patients had CNS thromboembolic complications. It is probable that low clotting factors, hyperfibrinolysis and thrombocytopenia (which are common in chronic liver disease) could have the opposite effect on hemostasis from that of low levels of anticoagulant proteins such as PC and AT III.
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PMID:Protein C and antithrombin III in polytransfused thalassemic patients. 310 18

We measured the plasma concentrations of the natural anticoagulant protein C and its cofactor protein S in 17 patients with severe proteinuria. In addition, prothrombin and antithrombin III levels were measured in the same group of patients. These results were compared with results obtained in 26 healthy controls and a group of 14 patients with chronic renal insufficiency (CRI) but minimal proteinuria. Protein C, protein S, and prothrombin levels were not significantly different between healthy controls and patients with CRI. However, protein C, protein S, and prothrombin levels were significantly elevated in 71%, 82%, and 76%, respectively, of patients with proteinuria. Antithrombin III levels were decreased in three of these 17 patients with proteinuria. Plasma concentrations of protein C, protein S, and prothrombin correlated significantly with each other and were inversely correlated with serum albumin concentrations. In three patients, high protein C, protein S, and prothrombin levels returned to normal during remission of the proteinuric state. Proteins C and S were not detectable in the urine of two patients with high-grade proteinuria. Thus, the plasma levels of the vitamin K-dependent, natural anticoagulant protein C and its cofactor protein S are increased in patients with proteinuria. The elevated plasma levels of other vitamin K-dependent proteins, such as prothrombin, suggest a generalized elevation in vitamin K-dependent protein synthesis in patients with proteinuria.
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PMID:Plasma concentrations of the natural anticoagulants protein C and protein S in patients with proteinuria. 316 Aug

Thromboembolic events remain one of the most serious complications in patients with nephrotic syndrome (NS). The natural anticoagulant system protein C-protein S was evaluated in patients with proteinuria and NS. Protein C levels were found to be normal or increased in NS. Protein C levels correlated positively with proteinuria, cholesterol and triglycerides and negatively with serum albumin. All of the 17 patients with NS exhibited urinary loss of protein C. Total protein S and C4BP were increased in mild and moderate forms of NS. Free protein S was identical in controls and NS patients. Nine of ten patients had urinary loss of protein S. No correlation was found between protein S and the various usual biologic parameters of NS. However, two patients with NS and thrombosis of the renal veins had an acquired deficit in either free protein S or protein C. Thus, in some patients, an acquired deficit in free protein S and/or protein C may contribute to the development of thrombotic complications in NS.
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PMID:[Proteins C and S of coagulation: new markers of thrombotic risk in nephrotic syndromes?]. 328 98

An infant with severe homozygous protein C deficiency was brought to medical attention because of purpura fulminans and severe bilateral vitreous hemorrhages in the neonatal period. Infusions of fresh frozen plasma were given for 8 months. On two occasions, attempts to decrease the frequency of fresh frozen plasma infusions to less than twice a day led to episodes of microangiopathic hemolysis, fibrinolysis, and acute renal failure. Infarction of skin and subcutaneous tissues did not recur. Both episodes were controlled after reinstitution of fresh frozen plasma. Complications of therapy with fresh frozen plasma included hyperproteinemia and hypertension. Warfarin therapy was instituted when the baby was 8 months of age, followed by a gradual withdrawal of fresh frozen plasma therapy. The dose of warfarin required to maintain the prothrombin time in a range of 1.8 to 2.2 times normal varied considerably during short periods, a phenomenon that may have been due to several factors: hypercatabolism of the drug with prolonged administration, abnormality of liver function, variation in levels of serum albumin, fluctuations in drug dosage secondary to oral administration, and variations in dietary vitamin K. Protein C determinations by immunologic and functional assays consistently showed detectable but reduced protein C antigen levels with undetectable activity levels, suggesting that a dysproteinemia rather than a deficiency of synthesis is responsible for the child's coagulopathy.
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PMID:Homozygous protein C deficiency: observations on the nature of the molecular abnormality and the effectiveness of warfarin therapy. 334 Apr 76


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