Bovine retina contains three growth factor activities with different affinity to heparin: eye derived growth factor I, II, III

Several ocular tissues have been shown to contain growth factor activity designated under a generic name as Eye Derived Growth Factor. Purification from bovine retina was undertaken and a fraction which could induce target cells to proliferate at doses of 5 ng per ml of culture medium was obtained. Using heparin sepharose chromatography we now show that this mitogenic activity can be fractionated into three different activities. Crude extract of bovine retina used as starting material was separated into two major fractions, one with no affinity for heparin and which was named Eye Derived Growth Factor III, and one with a strong affinity for heparin and eluted from the column with 1.4 M NaCl named Eye Derived Growth Factor I. This fraction EDGF I induces cell proliferation at doses of 100 pg/ml of culture medium. A 10(5) fold purification was achieved by this single chromatography step. Cibacron Blue purified EDGF was also further fractionated by heparin sepharose. All biological activity was found to bind to heparin. One fraction eluted at 1 M NaCl named Eye Derived Growth Factor II had a biological activity at doses of 1 ng while the other growth factor was the EDGF I with biological activity at 25 pg. At this step of purification EDGF I runs as a single band on SDS polyacrylamide gel at a molecular weight of 17 000 d. These data strongly suggest that Eye Derived Growth Factors I and II are respectively similar to Brain Fibroblast Growth Factor and to Endothelial Cell Growth Factor from hypothalamus.     

魔芋葡苷聚糖（KGM）凝胶为亲和层析载体与Sepharose4B的比较 …

将ＫＧＭ和Ｓｅｐｈａｒｏｓｅ ４Ｂ凝胶在相同条件下活化、偶联接上染料Ｃｉｂａｃｒｏｎ Ｂｌｕｅ Ｆ３ＧＡ制成了ＫＧＭ和Ｓｅｐｈａｒｏｓｅ ４Ｂ染料亲和吸附剂,并用来与牛血甭白蛋白（ＢＳＡ）作用,每毫升ＫＧＭ亲和吸附剂可吸附ＢＳＡ ２８ｍｇ,用ＮａＳＣＮ洗脱时间为８４．５％,而Ｓｅｐｈａｒｏｓｅ ４Ｂ染料样和吸附剂每毫升可吸附ＢＳＡ １５．３ｍｇ,用ＮａＳＣＮ洗脱时间收迷８１．７％,并对两种凝胶的染     

Purification of rat adipose tissue lipoprotein lipase by affinity chromatography.

Lipoprotein lipase (EC 3.1.1.3) from rat adipose tissue was purified by affinity chromatography with heparin-Sepharose. Elution was carried out with buffered solutions of increasing NaCl molarity. Proteins without affinity for heparin were eluted with 0.5 M NaCl, while lipoprotein lipase activity was eluted as two peaks with 1.16 M NaCl (In earlier work on human adipose tissue (Etienne et al. (1974) C.R. Acad. Sc. Paris 279, 1487-1490) two fractions with lipoprotein lipase activity were also obtained). Phospholipase activity was detected in the fraction eluted with buffered 0.5 M NaCl and containing proteins without affinity for heparin. On feeding the fasting rats with fresh cream or glucose two peaks were also obtained, but the first peak had clearly increased while the second one had remained virtually unchanged.     

Growth stimulating activity secreted by human anaplastic thyroid carcinoma cells.

In order to clarify the mechanism of rapid growth of anaplastic thyroid carcinoma, growth stimulating activity produced by the cancer cells in culture was studied. A cell line (HTh7) established from a biopsy specimen of anaplastic thyroid carcinoma was used throughout the study. Growth stimulating activity was determined as an activity to increase 3H-thymidine incorporation in rat thyroid cell line (FRTL5). Conditioned medium of HTh7 cells contained significant growth stimulating activity for FRTL5 cells. The activity was separated into two fractions with heparin agarose gel: heparin-binding and heparin-non-binding. In the medium, the heparin-non-binding activity was much greater than the heparin-binding one. The heparin-non-binding activity was acid stable. It was partially purified with gel filtration in an acidic condition followed by reverse phase HPLC. In gel filtration with a Sephacryl S-200 column, the activity was eluted later than the elution volume of cytochrome c (MW 12400) as several separated peaks. In reverse phase HPLC, however, the activity in these peaks was eluted as a single peak. The retention time of the active peak was almost the same as that of recombinant IGF-I. When measured by specific RIAs, the conditioned media concentrated 20 times contained both 0.35 ng/ml of IGF-I and 5.21 ng/ml of IGF-II. As for the heparin-binding mitogenic activity, when applied to heparin affinity HPLC column and eluted with a linear gradient of NaCl, the activity came out as one major peak with approximately 1.0 M NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)     

Selective precipitation-assisted recovery of immunoglobulins from bovine serum using controlled-fouling crossflow membrane microfiltration

Efficient and economic recovery of immunoglobulins (Igs) from complex biological fluids such as serum, cell culture supernatant or fermentation cell lysate or supernatant, represents a substantial challenge in biotechnology. Methods such as protein A affinity chromatography and anion exchange chromatography are limited by cost and selectivity, respectively, while membrane chromatography is limited by low adsorptive area, flow distribution problems and scale-up difficulties. By combining the traditional salt-assisted precipitation process for selective removal of Igs from serum followed by constant-permeate flux membrane microfiltration for low fouling, we demonstrate an exciting new, efficient and economic hybrid method. The high selectivity of an ammonium sulfate-induced precipitation step was used to precipitate the Igs leaving the major undesirable impurity, the bovine serum albumin (BSA), in solution. Crossflow membrane microfiltration in diafiltration mode was then employed to retain the precipitate, while using axial flow rates to optimize removal of residual soluble BSA to the permeate. The selectivity between immunoglobulin G (IgG) and BSA obtained from the precipitation step was approximately 36, with 97% removal of the BSA with diafiltration in 5 diavolumes with resulting purity of the IgG of approximately 93% after the membrane microfiltration step. Complete resolubilization of the IgG was obtained without any aggregation at the concentrations of ammonium sulfate employed in this work. Further, membrane pore size and axial Reynolds number (recirculation rate) were shown to be important for minimizing fouling and loss of protein precipitate.     

Localization of nitrogenase in vesicles of Frankia sp. Cc1.17 by immunogoldlabelling on ultrathin cryosections

Immunogoldlabelling on ultrathin cryosections of Frankia sp. Cc1.17 showed specific labelling of nitrogenase in the spherical cells called vesicles. No label was found in the hyphae in any cells grown on a medium with combined nitrogen, nor in those to which no specific antiserum was added. Similar results were obtained with cultures grown under high (20%) and low (2%) oxygen tension in the gas phase.Abbreviations BSA Bovine serum albumin fraction V (Sigma) - PBS phosphate buffered saline. Phosphate buffer 0.1 M, 8 g NaCl/1, 0.2 g KCl/1 - PIPES Piperazine-1,4-bis(ethane sulphonic acid)     

Isolation and partial characterization of mitogenic factors from cementum.

Cementum is the mineralized structure through which soft connective tissues are attached to the teeth. It is a unique calcified tissue characterized by a low metabolic turnover, lack of blood supply, and presence of very few cells. However, it contains substances that influence the biological activities of fibroblasts of adjacent soft tissues. We have partially characterized cementum proteins that have mitogenic activity toward fibroblasts. Cementum was harvested from bovine teeth, and mitogenic factors were extracted in 0.5 M CH3COOH. Heparin-Sepharose chromatography separated the mitogenic activity into a major and a minor fraction eluted by 0.5 and 2.0 M NaCl, respectively. The distribution of cementum mitogens in heparin-Sepharose fractions was different from that of alveolar bone and other bones. The cementum mitogenic factor eluting with 2.0 M NaCl from a heparin-Sepharose column was shown to be basic fibroblast growth factor (bFGF) on the basis of inhibition by anti-bFGF antibody and Western blots. The 0.5 M NaCl fraction was purified by HPLC with use of a combination of a DEAE-3W column followed by TSK-250 and C18 columns. NaDodSO4-polyacrylamide gel electrophoresis revealed that the purified fraction contained two protein bands with Mr 22,000 and 19,000, and mitogenic activity was associated with the Mr 22,000 species. The activity of this mitogen, designated as CGF, was potentiated by small quantities of plasma-derived serum or epidermal growth factor. It was heat resistant, but was destroyed by reduction. Assays of CGF preparations revealed that they contained no detectable platelet-derived growth factor.(ABSTRACT TRUNCATED AT 250 WORDS)     

Purification of an embryotrophic factor from commercial bovine serum albumin and its identification as citrate.

A factor of low M(r) with growth-promoting effects on rabbit embryos was extracted and purified from commercial bovine serum albumin (BSA). This embryotrophic factor was extracted from BSA dissolved in formic acid by membrane filtration (membrane cutoff of M(r) 10,000) and then freeze-drying of the filtrate. The extract was purified successively by chromatography on G-10 Sephadex, QAE-Sephadex A-25 anion exchange and high-performance liquid chromatography (HPLC) reverse-phase columns. Mass spectrometry of the active reverse-phase material indicated that the major component in this material had an M(r) of 192. The embryotrophic factor in the low M(r) extract of BSA was shown to be citrate, because: (i) the mass spectra of the active reverse-phase material and citrate were identical, (ii) the activity was eluted at the identical position to citrate on an analytical HPLC anion-exchange column, (iii) the original BSA sample was shown by enzyme assay to be heavily contaminated by citrate and (iv) citrate stimulated cell proliferation and expansion of blastocysts.     

Isolation and identification of a 23,000-dalton heparin binding fragment from the amino terminus of bovine thrombospondin

Bovine freeze-thaw lysed platelets were fractionated by dextran sulfate affinity chromatography and a purified protein of 23,000 Da was subsequently obtained by G-75 gel filtration of the 0.5 M NaCl fraction. This protein had an amino terminal sequence of Asn-Arg-Ile-Pro-Glu-Ser-Gly-Gly-Asp-Asn-Ser-Val-Phe-Asp-Ile-Phe-Glu-Leu- Thr-Gly-Ala-Ala-Trp-Lys-, a sequence identical to that reported for human thrombospondin. Thrombin-released platelets, fractionated in an identical manner, yielded a protein of 30,000 Da. Immunoblotting of purified bovine platelet thrombospondin and the 150,000- and 30,000-Da plasmin-generated thrombospondin fragments indicated that polyclonal antisera raised against the 23,000-Da protein cross-reacted with intact thrombospondin and the 30,000-Da fragment but not the 150,000-Da fragment. The 23,000-Da protein possessed weak heparin neutralization activity.     

Cell multiplication and type II collagen production by rabbit articular chondrocytes cultivated in a defined medium

The complexity and the variations in the efficiency of different batches of serum stimulated the preparation of a serum-free medium which could promote not only growth, but also the differentiation properties of rabbit articular chondrocytes in culture. The serum-free medium (SFM) developed in this study contained insulin, transferrin, Na-selenite, human fibronectin bovine serum albumin (BSA), brain growth factor (BGF) or fibroblast growth factor (FGF), hydrocortisone and multiplication stimulating activity (MSA). Primary or secondary cultures of chondrocytes in such a medium attained a proliferation rate equal to 70-80% of that obtained with chondrocytes grown in a serum control medium. The deletion of various factors from SFM indicates that BGF or FGF are the most stimulating of growth factors. Insulin was beneficial when used individually; when combined with BGF or FGF, they had a synergistic effect on cell proliferation. MSA seemed not to play any role in chondrocyte growth in culture. The SFM medium did not modify either the morphology or the progression of cells into the cell cycle. It moreover allowed the maintenance of the specific function of chondrocytes to synthesize type II collagen.     

Activation and inhibition of human cancer cell hyaluronidase by proteins

Results regarding hyaluronidase activity in tumor extracts or cell lines are subject to variations according to the method used for the assay and, sometimes, within an assay. Hyaluronidase was assayed at pH 3.8 in the culture medium of the human cancer-derived cell lines SA87 and H460M by several techniques: HPLC, Reissig technique, ELSA technique, and zymographic analysis. The optimal pH was between 3.3 and 4 in solutions at constant 150 mM sodium concentration. The enzyme was reversibly inhibited by sodium concentration over 200 mM. The activity of purified hyaluronidase increased in the presence of low concentrations of the specific HA-binding glycoprotein hyaluronectin, or of bovine serum albumin or immunoglobulins, or of human albumin, transferrin, or hemoglobin, showing that proteins cooperate in enzyme activity. The ELSA technique showed that optimal pH was slightly lower in the presence of HN than that with BSA. The optimal BSA concentration was determined with the ELSA technique at 0.1 g/liter, and excess of either protein inhibited hyaluronidase. When measured with the Reissig technique, the activity of purified enzyme in the presence of 0.1 g/liter BSA was up to fourfold that without BSA. The cooperative effect of BSA was visualized by zymography. We conclude that the total protein content of hyaluronidase solutions must be considered to correctly interpret quantitation of the enzyme in sera or tissue extracts because protein concentrations above 200 microg/liter lead to underestimation of the enzyme.     

Paraoxon hydrolysis in human serum mediated by a genetically variable arylesterase and albumin.

Gel filtration chromatography resolves human serum paraoxonase into two fractions: (1) a high molecular weight fraction that is completely inhibited by EDTA and coelutes with arylesterase (E.C.3.1.1.2); and (2) a second fraction that is closely associated with albumin, is only partially inhibited by EDTA, and has relatively little arylesterase activity under the assay conditions used. The activity of the high molecular weight fraction is stimulated by NaCl, whereas the albumin associated activity is partially inhibited by NaCl and is not present in serum derived from an analbuminemic individual. Our data suggest that albumin itself, rather than a protein bound to or cofractionating with albumin, mediates paraoxonase activity. The variation in levels of the activity of the nonalbumin, high molecular weight enzyme is responsible for the observed polymorphism of paraoxonase activity in human serum or plasma. An optimal assay of polymorphic paraoxonase activity should be based on activity measurements of the nonalbumin fraction. It is considered likely that only the nonalbumin fraction is responsible for in vivo hydrolysis of paraoxon.     

Species-dependency in chiral-drug recognition of serum albumin studied by chromatographic methods

Stereoselective binding of benzodiazepine and coumarin drugs to serum albumin from human and six mammalian species were studied by chiral chromatographic techniques. The applied methods were affinity chromatography on the albumins immobilized on Sepharose 4B, high-performance liquid chromatography (HPLC) separation on columns based on human serum albumin (HSA) and bovine serum albumin (BSA), and chiral HPLC analysis of ultrafiltrates of solutions containing the racemic drug and the native protein. Substantial differences in preferred configurations and conformations were detected among the species. The binding stereoselectivity of the 2,3-benzodiazepine drug, tofisopam, in human, is opposite to that in all other species. In the binding of 1,4-benzodiazepines, dog albumin is very similar to HSA. Highly preferred binding of (S)-phenprocoumon was found with dog albumin.     

Extraction of rIL-2 inclusion bodies from Escherichia coli using cross-flow filtration

A cross-flow membrane filtration process was developed for the recovery of rIL-2 inclusion bodies from homogenized Escherichia coli. The membrane extraction process was comprised of a two-step diafiltration followed by an extraction with 7 M GuHCl and a 40-fold dilution of the solubilized inclusion bodies into 0.01 M Tris-HCl, 0.035 M NaCl, pH 7.9. The first diafiltration was with a 0.03 M Tris-HCl, 5 mM ethylenediaminetetraacetic acid (EDTA), pH 8, followed by a diafiltration with 1.75 M GuHCl. All of the insoluble rIL-2 was retained behind the membrane, whereas a GuHCl wash solubilized approximately 15% of the rIL-2. The membrane process increased the yield of rIL-2 in the diluted extract by threefold as compared to a similar centrifuge process with a significant increase in purity as determined by reverse-phase high-performance liquid chromatography (HPLC). (c) 1994 John Wiley & Sons, Inc.     

Nutritional factors affecting the synthesis of an antiphagocytic factor by group E streptococci

Effects of components of the cultural medium on formation of a group E streptococcal antiphagocytic factor (APF), as detected by an indirect bactericidal test, were studied. Bovine serum albumin (BSA) replaced serum in promoting synthesis of APF in a chemically defined medium (CDM), Todd--Hewitt broth (THB), or tryptose phosphate broth ( TPB ). Stimulatory factors in BSA were not retained by diafiltration membranes of nominal molecular weight cutoff limits of 10 000 or greater. Citrate, lactate, pyruvate, or oleate, often found in BSA, could not replace BSA in stimulating synthesis of APF. Cells cultured in THB were more resistant to phagocytosis by porcine leukocytes than those grown in CDM or TPB , and the addition of varying amounts of THB to CDM stimulated a measurable response in synthesis of APF. Specific substrates caused different rates of APF synthesis; in decreasing order of effectiveness were glucose or mannose, sucrose, fructose, and trehalose. Proteolytic activity, which might cause the production of phagocyte-sensitive cells by destroying APF activity during culture, was not detectable in significant amounts in subcultures of the age employed in bactericidal tests.     

Separation of mouse crushed muscle extract into distinct mitogenic activities by heparin affinity chromatography

Extracts from gently crushed adult mouse skeletal muscles (CMEs) contain potent myoblast mitogens, and may be used as a model system to investigate myotrophic factors released by adult muscles following injury. CME was separated into four peaks of mitogenic activity by heparin affinity chromatography. The fraction of CME that did not bind to heparin contained transferrin (Tf). Three peaks of mitogenic activity were eluted from the heparin-agarose columns at NaCl concentrations of 0.4 M, 0.9 M, and 2.0 M. A 46 kDa protein that shared antigenicity with the BB isoform of platelet-derived growth factor (PDGF-BB) was present in the 0.4 M NaCl eluant. Mitogenic activity in the 2.0 M NaCl peak eluted identically to purified basic fibroblast growth factor (bFGF), did not act additively to saturating amounts of purified bFGF, and was neutralized by anti-bFGF antibodies. The 0.9 M NaCl eluant acted additively to the combination of three known growth factors for myoblasts, bFGF, insulin-like growth factor I, and epidermal growth factor, to stimulate C2 myoblast proliferation, suggesting this fraction contains a mitogenic activity which does not utilize (and hence compete for) receptors for the known mitogens for myoblasts. Additionally, the 0.9 M NaCl eluant did not stimulate proliferation of fibroblast-like cells derived from muscle tissue. The unbound, 0.4 M NaCl, 0.9 M NaCl, and 2.0 M NaCl eluants from the heparin-agarose column acted additively to one another to stimulate myoblast proliferation. Our data suggest that Tf, PDGF-BB-like molecules, bFGF-like activity, and an uncharacterized heparin-binding myoblast mitogen could be released after muscle injury and act to stimulate satellite cell proliferation. © 1994 Wiley-Liss, Inc.     

Heparin inhibits the activity of protein phosphatase-1

Heparin inhibited the dephosphorylation of rabbit skeletal muscle or liver phosphorylase a by protein phosphatase-1. Other glycosaminoglycans (chondroitin sulfates) and their constituents were found to be without effect. The chromatography of a partially purified phosphatase preparation on heparin-Sepharose CL-6B resulted in a fraction that did not bind to the matrix and its activity was not inhibited by heparin or inhibitor-1. The phosphatase bound to heparin-Sepharose was eluted by 0.2 M NaCl and was inhibited by heparin or inhibitor-1.     

A serum-free medium for hybridoma cell culture

The effects of several different substances, including insulin, transferrin, ethanolamine, selenite and butyrate on the growth of murine hybridoma 2F7 cells, which secrete monoclonal antibody against small cell lung cancer, were investigated, and a serum-free medium SFMI was formulated. The effects of taurine, spermidine, progesterone and adenine on the cell growth were tested further on the basis of the medium SFMI, and a modified serum-free medium SFM II was established. On the basis of medium SFM II, the substitution tests of ferric citrate for transferrin were carried out, and it was found that transferrin could be replaced. The experiments suggested that the formulated serum-free medium was suitable for 2F7 cell growth and monoclonal antibody secretion, and thus facilitated subsequent purification of monoclonal antibody.Abbreviations BSA bovine serum albumin - CS calf serum - DMEM Dulbecco's modified Eagle's medium - ELISA enzyme-linked immunosorbant assay - McAb monoclonal antibody - PEG polyethylene glycol - SFM serum-free medium     

Fractionation of chylomicrons by heparin-sepharose chromatography. Characterization of two heparin-binding proteins

Rat lymph chylomicrons were separated into two fractions using heparin-Sepharose chromatography: a major fraction which elutes from the column with the void volume at 0.05 M NaCl, and a smaller fraction which binds to the column at 0.05 M NaCl and elutes at 0.3 M NaCl. These two fractions differ in mean particle size, and lipid and protein compositions. Both fractions share apolipoproteins B, A-IV, E, A-I, and C, but the fraction which binds to heparin-Sepharose contains two additional proteins: protein I (Mr = 6.0 X 10(4)), and protein II (Mr = 8.0 X 10(4)). Both proteins are also present in the lipoprotein-free fraction of rat serum. Proteins I and II bind to heparin-Sepharose, and are highly amphiphilic: they bind with high affinity to phospholipid surfaces and form stable monolayers at the air-water interface. The molecular weight, amino acid composition, heparin binding, and amphiphilicity of protein I resemble that of beta 2-glycoprotein I; in addition, protein I from rat lymph chylomicrons cross-reacts with rabbit antiserum to human beta 2-glycoprotein I, suggesting that these two proteins are homologous. Protein II appears to be a previously undescribed protein. The possible functions of these two proteins are discussed.     

Multiple aflatoxin B1 binding proteins exist in rat liver cytosol

The in vitro binding of aflatoxin B1 to rat liver cytosolic proteins was investigated. Aflatoxin B1 binding activity was assayed with protein purified by gel permeation chromatography, ammonium sulfate fractionation, and DEAE-cellulose chromatography. Twenty-five percent of the total binding activity was associated with proteins eluted by 0 and 0.1 M NaCl. Over 50% of the total binding activity was associated with protein present in the 0.2 M NaCl fraction. Glutathione S-transferase activity was also monitored and found only in the low salt (less than 0.2 M NaCl) fractions. The proteins eluted by 0.2 M NaCl were further purified by hydroxylapatite column chromatography and binding was found predominantly in a single fraction. The protein purification steps resulted in a 20-fold increase in the specific binding activity over that initially observed in the cytosol. These results indicate that multiple proteins are capable of binding aflatoxin B1 in rat liver cytosol.