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1.
Mol Immunol ; 28(3): 251-5, 1991 Mar.
Article in English | MEDLINE | ID: mdl-2017196

ABSTRACT

A novel process for preparing non-pyrogenic toxoids of pertussis toxin (PT) and filamentous hemagglutinin (FHA) is described. The process consists of chromatographies on perlite then on hydroxylapatite. Purification yields for PT and FHA are 62 and 68%, respectively. The purification process takes advantage of the novel use of perlite (a filter aid) for the simultaneous purification of PT and FHA. The hydroxylapatite, in addition to removing the remaining contaminants, also concentrates the antigens. The resulting PT and FHA are approximately 95% pure, and are non-pyrogenic as judged by the rabbit pyrogen test. The purification process is simple, inexpensive, and does not use blood components or toxic substances. The mild conditions in which the PT and FHA are purified ensure the recovery of native protein. The purified PT and FHA are detoxified in the presence of glycerol using glutaraldehyde and formaldehyde, respectively, to produce antigenic components of an acellular pertussis vaccine. The final PT and FHA toxoids are immunogenic in guinea-pigs and have been shown to be protective in the mouse intracerebral challenge test.


Subject(s)
Pertussis Toxin , Pertussis Vaccine/immunology , Virulence Factors, Bordetella/isolation & purification , Bordetella pertussis/analysis , Bordetella pertussis/immunology , Hemagglutinins/immunology , Hemagglutinins/isolation & purification , Molecular Weight , Pyrogens/analysis , Virulence Factors, Bordetella/immunology
3.
Biochem Cell Biol ; 65(9): 822-32, 1987 Sep.
Article in English | MEDLINE | ID: mdl-3125847

ABSTRACT

Two enzyme complexes, each with beta-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21), beta-xylosidase (beta-D-xylan xylohydrolase, EC 3.2.1.37), and 1,3-beta-glucanase (laminarinase, EC 3.2.1.39) activity, were purified to near homogeneity from the cellulolytic fungus Trichoderma harzianum E58. The two complexes had the same isoelectric point of pH 8.3 and identical subunit molecular masses of 75,400 daltons. The two complexes were also similar in that all activities were sensitive to inhibition by mercuric chloride (2 mM) and D-glucono-1,5-lactone (0.2% w/v). The activity ratios of the major and minor complexes were 1:1.7:4.3 and 1:1.6:3.1 for the beta-xylosidase, beta-glucosidase, and 1,3-beta-glucanase, respectively. Both complexes had approximately the same Km values for p-nitrophenyl beta-D-glucopyranoside and salicin. The pH optima of corresponding activities of the two complexes were also similar. The major and minor complexes differed in that the Km of the former for laminarin was almost threefold lower than that of the latter. Whereas all three activities of the minor complexes were inhibited by D-glucono-1,5-lactone with the same inhibition constant, the beta-glucosidase and 1,3-beta-glucanase of the major complex had inhibition constants which differed by more than 80,000 times. In addition, the inhibition on the 1,3-beta-glucanase in the major and minor complexes using D-glucono-1,5-lactone were noncompetitive and competitive, respectively. From the inhibition studies, the beta-glucosidase, beta-xylosidase, and 1,3-beta-glucanase activities in the minor complex were deduced to be more interdependent than the same activities in the major complex.


Subject(s)
Glucosidases/isolation & purification , Glycoside Hydrolases/isolation & purification , Mitosporic Fungi/enzymology , Trichoderma/enzymology , Xylosidases/isolation & purification , beta-Glucosidase/isolation & purification , Chromatography, Ion Exchange , Electrophoresis, Polyacrylamide Gel , Glucan 1,3-beta-Glucosidase , Hydrogen-Ion Concentration , Isoelectric Focusing , Kinetics , Temperature , Xylosidases/metabolism , beta-Glucosidase/metabolism
4.
Biotechnol Bioeng ; 30(1): 96-100, 1987 Jul.
Article in English | MEDLINE | ID: mdl-18576588

ABSTRACT

A process has been developed for the bulk purification of cellulase-free beta-1,4-D-xylanase from the fungus Trichoderma harzianum E58. The process involved the primary step of ultrafiltering the culture filtrate via a 10,000-molecular-weight cut-off membrane to separate the cellulase (retentate) and xylanase (permeate) fractions. The cellulase component was concentrated by 40- to 60-fold, resulting in an enzyme complex that could effectively hydrolyze high concentrations of cellulose and xylan to glucose and xylose. The xylanase was concentrated and solvent exchanged by adsorption to a cationic exchanger, SP-ZetaPrep 250, followed by elution with a pH change in the buffer to give a purified and concentrated xylanase complex dissolved in a low-salt buffer. The resultant xylanase system was pure by the criteria of sodium dodecyl sulfate polyacrylamide electrophoresis, had a very high specific activity of 2400 IU/mg protein, was virtually free of filter paper activity, and had a ratio of contaminating filter paper activity of 2 x 10(-6) (0.009% endoglucanase activity). Approximately 3.3 g protein, which contained in excess of 7 x 10(6) IU xylanase activity, was obtained from 17 L original culture filtrate. The process scheme was designed to facilitate scale-up to an industrial level of production.

5.
J Mol Biol ; 194(4): 755-6, 1987 Apr 20.
Article in English | MEDLINE | ID: mdl-3656407

ABSTRACT

A 20,000 Mr xylanase from Trichoderma harzianum has been purified and crystallized from 20% (w/v) saturated ammonium sulphate solutions. The unit cell is orthorhombic, space group P2(1)2(1)2(1), with unit cell lengths a = 44.2 A, b = 94.1 A, c = 51.6 A. Data from native crystals and several potential heavy-atom derivatives have been collected. An X-ray analysis to at least 2.8 A resolution appears to be feasible.


Subject(s)
Glycoside Hydrolases , Mitosporic Fungi/enzymology , Trichoderma/enzymology , Crystallization , X-Ray Diffraction , Xylan Endo-1,3-beta-Xylosidase
6.
Mol Biol Rep ; 12(4): 285-9, 1987.
Article in English | MEDLINE | ID: mdl-3431544

ABSTRACT

A method is described for the rapid analysis of DNA ligation products in the assembly of synthetic genes and gene fragments. The method is based on the simultaneous analysis of multiple ligation reactions where a single but different DNA oligomer is radiolabelled per ligation reaction. After each ligation the reaction mixture is electrophoresed on a denaturing, as well as a non-denaturing, polyacrylamide gel allowing one to monitor the ligation reaction products. In addition, a unique method for generating single stranded DNA sizing standards up to approximately 300 nucleotides in length is described.


Subject(s)
Oligodeoxyribonucleotides/analysis , Base Sequence , DNA, Single-Stranded , Electrophoresis, Polyacrylamide Gel , Nucleic Acid Denaturation , Oligodeoxyribonucleotides/chemical synthesis , Reference Standards
9.
Can J Biochem ; 57(6): 806-12, 1979 Jun.
Article in English | MEDLINE | ID: mdl-476523

ABSTRACT

Chymotryptic cleavage of the trifunctional protein methylenetetrahydrofolate dehydrogenase-methenyltetrahydrofolate cyclohydrolase-formyltetrahydrofolate synthetase from pig liver yields a fragment of two-thirds the original polypeptide that retains only synthetase activity. A smaller polypeptide corresponding to about one-third of the original polypeptide was shown earlier to retain dehydrogenase-cyclohydrolase activity. On immunodiffusion, the synthetase fragment cross-reacts and shows partial identity with antibodies raised against the uncleaved enzyme but shows nonidentity with the dehydrogenase-cyclohydrolase fragment, suggesting that the two fragments are derived from different regions of the polypeptide. Amino-terminal analysis of the peptides and uncleaved enzyme indicate that the dehydrogenase-cyclohydrolase activities are located at the amino-terminal region and the synthetase near the carboxyl-terminal portion of the polypeptide.


Subject(s)
Aminohydrolases/metabolism , Formate-Tetrahydrofolate Ligase/metabolism , Ligases/metabolism , Methylenetetrahydrofolate Dehydrogenase (NADP)/metabolism , Multienzyme Complexes/metabolism , Oxidoreductases/metabolism , Amino Acid Sequence , Animals , Formate-Tetrahydrofolate Ligase/analysis , Tetrahydrofolates/metabolism
10.
Biochim Biophys Acta ; 485(1): 52-9, 1977 Nov 23.
Article in English | MEDLINE | ID: mdl-562190

ABSTRACT

Tryptic digestion of a multifunctional enzyme from porcine liver containing methylenetetrahydrofolate dehydrogenase (5,10-methylenetetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.5), methenyltetrahydrofolate cyclohydrolase (5,10-methenyltetrahydrofolate 5-hydrolase, EC 3.5.4.9) and formyltetrahydrofolate synthetase (formate:tetrahydrofolate ligase, EC 6.3.4.3) activities destroys the synthetase. A fragment containing both dehydrogenase and cyclohydrolase activities has been isolated by affinity chromatography on an NADP+-Sepharose affinity column. The purified fragment is homogeneous on dodecyl sulfate-polyacrylamide gel electrophoresis where its molecular weight was determined as 33 000 +/- 1200 compared with 100 000 for the undigested protein. The cyclohydrolase activity retains sensitivity to inhibition by NADP+, MgATP and ATP.


Subject(s)
Aminohydrolases/isolation & purification , Formate-Tetrahydrofolate Ligase/isolation & purification , Ligases/isolation & purification , Liver/enzymology , Methylenetetrahydrofolate Dehydrogenase (NADP)/isolation & purification , Multienzyme Complexes/isolation & purification , Oxidoreductases/isolation & purification , Animals , Electrophoresis, Polyacrylamide Gel , Molecular Weight , Swine , Tetrahydrofolates , Trypsin
11.
J Biol Chem ; 252(3): 1117-22, 1977 Feb 10.
Article in English | MEDLINE | ID: mdl-838698

ABSTRACT

Methylenetetrahydrofolate dehydrogenase, methenyltetrahydrofolate cyclohydrolase, and formyltetrahydrofolate synthetase from porcine liver have been co-purified more than 500-fold to apparent homogeneity. The inability of three sequential chromatographic procedures followed by affinity chromatography using NADP+- or ATP-substituted Sepharose to resolve the three activities demonstrates that they are physically associated. Molecular weight estimates of the native protein by gel filtration (Mr = 150,000) and by dodecyl sulfate gel electrophoresis (Mr = 100,000) indicate that the native structure is probably a single subunit. Since only one protein band is seen on dodecyl sulfate gels, it is concluded that the three activities are properties of a single polypeptide chain. The kinetic properties of the three activities are described, the most unusual feature being the susceptibility of the cyclohydrolase to competitive inhibition by NADP+, NAD+, ATP, and folate.


Subject(s)
Aminohydrolases , Formate-Tetrahydrofolate Ligase , Ligases , Liver/enzymology , Methylenetetrahydrofolate Dehydrogenase (NADP) , Multienzyme Complexes , Oxidoreductases , Aminohydrolases/isolation & purification , Aminohydrolases/metabolism , Animals , Formate-Tetrahydrofolate Ligase/isolation & purification , Formate-Tetrahydrofolate Ligase/metabolism , Kinetics , Ligases/metabolism , Methylenetetrahydrofolate Dehydrogenase (NADP)/isolation & purification , Methylenetetrahydrofolate Dehydrogenase (NADP)/metabolism , Molecular Weight , Multienzyme Complexes/isolation & purification , Multienzyme Complexes/metabolism , Oxidoreductases/metabolism , Swine , Tetrahydrofolates
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