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At least 19 recordsLinked to original sources
PubMed2000

Laboratory scaledown of protein purification processes involving fractional precipitation and centrifugal recovery.

The ability to predict the performance of large-scale processes is central to the rapid development of successful operations at the pilot and industrial scale. In this article, we examine the operation, at laboratory scale, of precipitation reactors and centrifuges for protein precipitate recovery and dewatering and how they might best mimic large-scale reactors and centrifuges, in this case, a pilot-scale batch stirred-tank reactor and a multichamber-bowl centrifuge. Novel approaches to bench-top centrifuge operation are provided, in particular with a view to delivery of material for subsequent high-resolution purification, which would be obtained at full pilot scale. Results are presented in terms of properties of the protein precipitates, the fraction of solids recovered, and the extent of dewatering achieved. Good agreement was obtained at bench scale (a 1000-fold scale down factor) for all of these parameters for pilot-scale, batch-feed operation. In addition, the methodology developed allows identification of the extent of break-up that occurs in continuous-feed centrifuges when processing shear-sensitive materials such as the protein precipitates studied here.

Alcohol Dehydrogenase↗
PubMed1979

Elevated heparin-precipitable fraction of plasma in granuloma annulare.

The levels of heparin-precipitable fraction of plasma were determined in 17 patients with granuloma annulare and 26 persons used as controls. The mean level in patients was greater than the mean level in persons used as controls (P LESS THAN .05). Patients with widespread, disseminated lesions tended to have higher levels than patients with more localized disease (P LESS THAN .15). New lesions were actively forming in two patients with widespread disease at the time of study, and levels of heparin-precipitable fraction in these patients were among the highest found. The significance of these findings and their relationship to the etiopathogenesis of granuloma annulare is speculative.

Adult↗
PubMed1977

Interactions among heparin, cold-insoluble globulin, and fibrinogen in formation of the heparin-precipitable fraction of plasma.

Fibrinogen and the cold-insoluble globulin of plasma (CIg) are the main protein components of the heparin-precipitable fraction of normal plasma. The interactions among these proteins and heparin were examined. Heparin formed a cold-precipitable complex with purified CIg or with mixtures of CIg and fibrinogen but not with purified fibrinogen alone. Cryoprecipitation was augmented by addition of Ca(++) or by selection of optimal heparin levels; it was reduced or even abolished by raising the ionic strength or pH or both, or by raising the heparin concentration above that for maximum precipitation of CIg. Fibrinogen reduced the threshold for heparin-induced CIg cryoprecipitation and, by coprecipitating with heparin and CIg, increased the amount of precipitate that formed. In contrast to the heparin-precipitable fraction of normal plasma which contained both fibrinogen and CIg, that from a patient with congenital afibrinogenemia contained CIg but lacked fibrinogen. Normal plasma depleted of CIg by immunoabsorption failed to form a heparin-induced cryoprecipitate. Thus, CIg is essential for heparin-induced cryoprecipitation to occur. Fibrinogen, as assessed by chromatographic experiments with heparin-Sepharose columns, had a considerably lower binding affinity for heparin than did CIg, suggesting that it participates in precipitate formation mainly, if not entirely, by virtue of its affinity for CIg. The region of the fibrinogen molecule accounting for its precipitation with CIg appears to be localized in the carboxy-terminal segment of the Aalpha-chain; fibrinogen subfractions lacking this region failed to augment cryoprecipitation of heparin-CIg mixtures and, even though such species were present in normal plasma, they failed to coprecipitate in the heparin-induced complex.

Calcium↗
PubMed1975

Deposition of fibrinogen (FR-antigen) in skin diseases. I. Psoriasis vulgaris and Psoriasis arthropathica (with special reference to heparin-precipitable fraction).

Twenty-five in-patients with psoriasis arthropathica (ps.a.) and 18 in-patients with psoriasis vulgaris (ps.v.) were examined for cryofibrinogen as heparin-precipitable fraction (HPF), for total fibrinogen in plasma and by immuno-fluorescence (IF) technique for FR-antigen in tissue sections of affected and unaffected skin. A control group of 14 in-patients with various non-psoriatic dermatoses were examined with if for FR-antigen in unaffected skin. Pathological quantities of HPF were found in 6% in ps.v. and in 48% in ps.a. Total fibrinogen in plasma was normal in ps.v. (365 mg%), and moderately elevated in ps.a. (471 mg%). In psoriatics, FR-antigen was found in unaffected skin ps.v. in 50%, in ps.a. in 72%. In affected skin, the figures were 67% and 84% respectively. No direct relationship could be found between the incidence and the degree of HPF, and depositions of FR-antigen in the tissue sections in the skin at the time of the examination. In the control group, no FR-antigen could be found in unaffected skin, except in one case of acne cystica, with traces of FR-antigen in a few areas of the tissue section.

Adult↗
PubMed1989

Schistosoma japonicum: the effect of serum fractions precipitated by ammonium sulfate on viability of schistosomula.

The effect of serum fractions precipitated by a saturated ammonium sulfate solution on viability of Schistosoma japonicum schistosomula was investigated. Axenized cercariae were incubated for 10 days at 37 degrees C in NCTC 109 supplemented with the 34%, 40%, 50%, 62% and 68% fractions of human or rabbit serum in an equivalent concentration to 10% serum. Only larvae cultured in media with the 68% fraction of human or rabbit serum retained the transparent feature and active motility, while the larvae cultured in other media became opaque and immotile. This was also true in media with human serum albumin or fatty acid-free human serum albumin at concentrations of 1.0 and 10.0 mg/ml of NCTC 109. On 10-day culture a part of larvae in the medium with the 68% fraction of human serum began to feed on red blood cells and the intestine was nearly closed by 21 days. These results suggest that serum fraction of 68% ammonium sulfate consisting of albumin is an important constituent in supporting the further growth of schistosomula in vitro.

Ammonium Sulfate↗
PubMed1998

Application of free-flow electrophoresis to the purification of trichosanthin from a crude product of acetone fractional precipitation.

The application of free-flow electrophoresis (FFE) to the purification of trichosanthin (TCS) from a crude product of acetone fractional precipitation was investigated. An electrophoresis technique, combining field step electrophoresis (FSE) and zone electrophoresis (ZE) to a one-step procedure, was optimized until a satisfactory purification factor (1.35), high resolution, and purity (>99%) were achieved. Testing several separation buffer systems revealed that a throughput of 14.2 mg/h can be obtained when the very basic TCS (pI 10.1) was dissolved and electrophoresed in a phosphate buffer system of pH 4. The purity of electrophoresed trichosanthin was proved by a variety of analytical methods, such as sodium dodecyl sulfate (SDS)-gel electrophoresis, capillary isoelectric focusing (CIEF), and sequencing of N- and C-termini. The high purity and large throughput achieved at low cost by using FFE indicates that this method can be employed for TCS purification.

Acetone↗
PubMed1984

Does qualitatively altered fibrinogen contribute to the increased heparin precipitable fraction (HPF) in acute myocardial infarction (AMI)?

The amount and protein composition of heparin precipitable fraction (HPF), and the plasma concentrations of fibrinogen, fibronectin, alpha 1-acid glycoprotein, alpha 1-antitrypsin, haptoglobin and C-reactive protein (CRP) were determined in healthy subjects as well as during the course of acute myocardial infarction (AMI). In all samples tested, HPF consisted nearly exclusively of fibrinogen and fibronectin. In the small precipitates from healthy subjects, approximately equal amounts of these two proteins were recovered. During the first days of AMI, plasma fibrinogen increased 2-3 fold. At the same time, however, the amount of HPF increased 5-10 fold. This increase was associated with increased precipitation of fibrinogen, whereas no simultaneous increase in fibronectin was found. In fact, a slight drop in plasma as well as HPF-fibronectin was regularly observed during this period. During the following week HPF returned to normal values, whereas the plasma fibrinogen remained elevated. No satisfactory explanation for this discrepancy can be offered at present. Thus, no evidence could be provided that other acute phase proteins than fibrinogen itself were involved. Some experiments, however, indicated qualitative changes in the fibrinogen participating in the HPF precipitation. Further studies are necessary to clarify this point. Such studies are in progress.

Acute-Phase Proteins↗
PubMed1985

Evidence that changes in fibrinogen quality during acute phase reactions are of major importance for the amount of heparin precipitable fraction (HPF).

The influence of qualitative and quantitative changes in plasma fibrinogen upon the amount of heparin precipitable fraction (HPF), obtained during the course of acute disease states, were examined. Whereas fibrinogen in plasma includes 3 species of different molecular weights (HMW, LMW, LMW'), fibrinogen in HPF, from normal as well as from "acute phase" plasma, consisted almost exclusively of HMW-fibrinogen (3% SDS-PAGE). Sub-unit chain electrophoresis (10% PAGE-SDS and two-dimensional electrophoresis) did not disclose any signs of abnormalities in the fibrinogen precipitated in HPF. Studies on patients revealed that the composition of plasma fibrinogen changed (increased HMW) during the course of acute myocardial infarction and following hip operations, and indicated that the amount of HPF was governed by the relative amount of HMW-fibrinogen as well total fibrinogen. This assumption was strengthened by quantitating the amount of HPF obtained after addition of highly purified HMW and LMW fibrinogen to normal and "acute phase" plasma. It is concluded that fibrinogen quality (per cent HMW or HMW/LMW ratio) is of major importance for the amount of HPF, thereby explaining some of the HPF-variations seen during the course of acute diseases.

Acute Disease↗
PubMed1985

Solubilisation and fractional precipitation of a steroid alpha-ketol oxidase.

An alpha-ketol oxidase that converts deoxycorticosterone to pregnenoic acid has been solubilised and fractionally precipitated with polyethylene glycol from rabbit liver microsomes. Maximal activity was obtained with the 12-14% fraction. Activity was linear with cytochrome P-450 concentrations up to 0.2 nmol and was inhibited with carbon monoxide.

Aldehyde Oxidoreductases↗
PubMed1991

[The significance of the heparin precipitable fraction in lung diseases].

The authors recently experienced a case of idiopathic interstitial pneumonia (IIP) that exhibited skin ulcers due to increased heparin precipitable fraction (HPF) in plasma. This case prompted us to investigate the occurrence and significance of HPF in interstitial pneumonia (IP). The subjects included patients with IIP (acute exacerbation 6 cases, chronic active stage 12 cases), IP associated with collagen vascular disease (CVD) (9 cases) and granulomatous lung diseases (7 cases). The data indicated that all of the cases with acute exacerbation of IIP exhibited increased plasma HPF values (218-951 mg/dl) compared to those of normal controls (less than 180 mg/dl). In contrast, the values ranged within normal limits in all of the cases with IP associated with CVD. In a companion study, we measured plasma HPF values in patients with lung cancer, bacterial pneumonia and diffuse panbronchiolitis. It was found that 22% of the subjects showed increased plasma HPF values. We also investigated whether there were correlations between plasma HPF and various inflammatory parameters. The data revealed that there were correlations between HPF and ESR, CRP, alpha 1-globulin, alpha 2-globulin, complement (C3) or fibrinogen. However, there was no correlation between HPF and fibronection. These results suggest that plasma HPF is valuable to evaluate the acute exacerbation of IIP, although the elevation of plasma HPF levels is not specific.

Acute-Phase Reaction↗
PubMed1980

Fibrinolytic activity of salivary euglobulin fractions precipitated at pH 5.9 or 6.4 before and after mixing with blood.

Mixed saliva was collected from 20 healthy young persons before oral surgery, immediately after the operation and at control 5 days later. The fibrinolytic activity of untreated whole saliva and salivary euglobulin fractions precipitated at pH 5.9 (10 patients) or at pH 6.4 (10 patients) was measured on human fibrin plates. The salivary euglobulin fractions were also processed on plasminogen-free fibrin plates. The concentrations of alpha 1-antitrypsin, antithrombin III, C1-esterase inhibitor, alpha 2-macroglobulin, alpha 2-plasmin inhibitor and plasminogen were measured in pooled plasma and four postoperative saliva samples before and after preparing the corresponding dissolved euglobulins precipitated at pH 5.9 or pH 6.4. Dissolved euglobulins from the pooled plasma were subjected to crossed immunoelectrophoresis with antisera to plasminogen in the second-dimension gel. Normal mixed saliva showed unaltered fibrinolytic activity after euglobulin precipitation, whereas euglobulins prepared from postoperative samples had higher activity than the untreated specimens. No significant differences of fibrinolytic activity between salivary euglobulins precipitated at pH 5.9 and 6.4 were demonstrated. The recovery of proteinase inhibitors in the euglobulin fractions of plasma is lower than 2.1% except C1-esterase inhibitor, which is precipitated, but only at pH 5.9. The mixing with saliva does not seem to change this relative quantity of precipitated inhibitors from plasma. Plasminogen precipitated from plasma is not proteolytic degraded and the yield is higher at pH 5.9 than at pH 6.4. Salivary euglobulins precipitated at pH 5.9 or 6.4 are superior to untreated saliva to measure the fibrinolytic activity of mixed saliva, especially in samples contaminated with blood.

Blood↗
PubMed1985

Immunochemical study on the mannans of Candida albicans NIH A-207, NIH B-792, and J-1012 strains prepared by fractional precipitation with cetyltrimethylammonium bromide.

The mannans of Candida albicans NIH A-207 (A strain, serotype A), C. albicans NIH B-792 (B strain, serotype B), and C. albicans J-1012 (J strain, serotype C) prepared by fractional precipitation with cetyltrimethylammonium bromide (Cetavlon) were investigated for their immunochemical properties. Upon treatment with 10 mM HCl at 100 degrees C for 60 min, the mannans of A and B strains each released a mixture of manno-oligosaccharides ranging from hexaose to mannose together with (for each one) an acid-modified mannan, while J-strain mannan released lower oligosaccharides, tetraose to mannose. The acid-modified mannan of B strain did not show antibody-precipitating activity against homologous antiserum, whereas acid-modified A- and J-strain mannans retained most of this activity. The acid-released oligosaccharides were assumed to consist of beta-1,2-linked D-mannopyranosyl residues from the results of specific rotation and proton magnetic resonance studies.

Antigens, Fungal↗
PubMed1975

Deposition of fibrinogen (FR-antigen) in skin diseases. II. Pustulosis palmaris et plantaris (with special reference to heparin-precipitable fraction).

Ten out-patients with pustulosis palmaris et plantaris were examined with direct immunofluorescence (IF) technique for deposition of fibrinogen, fibrin or its degradation products (FR-antigen) in affected and unaffected skin, together with heparin-precipitable fraction (HPF), cryoglobulin and total plasma fibrinogen in the blood. FR-antigen was found in all cases in affected skin as a uniform pattern of a continuous ramification below the dermo-epidermal junction. This IF picture was absent in unaffected skin, but in other parts of the dermis in affected and unaffected skin, scattered streaks of IF could be seen. In one case, however, unevenly distributed IF was found in unaffected skin in the junction area. The scattered IF was also present in a minor degree in affected and unaffected skin in a control material of other dermatoses. Only one patient had slightly elevated values of HPF (0.33 mg/ml). Total plasma fibrinogen was insignificantly elevated, and no cryoglobulin could be found.

Adult↗