PubMed Health⌕ Search

Biomedical subjects

T M Enari

Publications and source records attributed to T M Enari.

14 recordsLinked to original sources

Fertile transgenic barley to particle bombardment of immature embryos.

Transgenic, fertile barley (Hordeum vulgare L.) from the Finnish elite cultivar Kymppi was obtained by particle bombardment of immature embryos. Immature embryos were bombarded to the embryonic axis side and grown to plants without selection. Neomycin phosphotransferase II (NPTII) activity was screened in small plantlets. One out of a total of 227 plants expressed the transferred nptII gene. This plant has until now produced 98 fertile spikes (T0), and four of the 90 T0 spikes analyzed to date contained the nptII gene. These shoots were further analyzed and they expressed the transferred gene. From green grains, embryos were isolated and grown to plantlets (T1). The four transgenic shoots of Toivo (the T0 plant) produced 25 plantlets as T1 progeny. Altogether fifteen of these T1 plants carried the transferred nptII gene as detected with the PCR technique, fourteen of which expressed the nptII gene. The integration and inheritance of the transferred nptII gene was confirmed by Southern blot hybridization. Although present as several copies, the transferred gene was inherited as a single Mendelian locus into the T2 progeny.

Base Sequence↗

A new appraisal of the endoglucanases of the fungus Trichoderma reesei.

The properties and enzymic activity of endoglucanases (EC 3.2.1.4) of the fungus Trichoderma reesei were studied by means of immunological methods and by using polyglycosidic substrates. Endoglucanases exist in the culture liquid as a series of immunologically related components. The most active endoglucanase component has an Mr of 43 000 and pI value of 4.0. The most abundant components have a value of pI about 5.0, an Mr of 56 000-67 000 and specific activity only one-fifth of that of the pI-4.0 component. During purification and storage the endoglucanases are spontaneously modified; the relative proportion of components having greater Mr values, more alkaline pI values and lower specific activities is increased. The hexose content of the endoglucanase components is 2-7%. Endoglucanases hydrolyse soluble beta-1,4 glycans. The enzymes described here differ from endoglucanase preparations described previously in not showing activity towards insoluble substrates. The role of endoglucanases in wood hydrolysis is consequently limited to the stage where wood constituents are already in soluble form.

Cellulase↗

Measurement of xylanase activity with insoluble xylan substrate.

Insoluble xylan was prepared from ground birch (Betula pubescens) pulp by alkali extraction and precipitation with ethanol. The only sugar detected after acid hydrolysis of the preparation was xylose. The insoluble xylan was used as substrate in a nephelometric assay to determine the xylanase (EC 3.2.1.8, 1,4-beta-D-xylan xylanohydrolase and EC 3.2.1.37, 1,4-beta-D-xylan xylohydrolase) activities of Aspergillus and Trichoderma enzymes. The nephelometric method is reliable in evaluating xylanase hydrolysis of insoluble xylan.

Aspergillus↗

Cellobiohydrolase from Trichoderma reesei.

A 1,4-beta-D-glucan cellobiohydrolase (EC 3.2.1.91) was purified from the culture liquid of Trichoderma reesei by using biospecific sorption on amorphous cellulose and immunoaffinity chromatography. A single protein band in polyacrylamide-gel electrophoresis and one arc in immunoelectrophoresis corresponded to the enzyme activity. The Mr was 65 000. The pI was 4.2-3.6. The purified enzyme contained about 10% hexose. The enzyme differs from previously described cellobiohydrolases in being more effective in the hydrolysis of cellulose.

Cellulose 1,4-beta-Cellobiosidase↗

Microbiological, biochemical, and electron microscopic characterization of a pectinatus strain.

A spoilage organism isolated from turbid beer is described. The bacterium was gram negative, catalase negative, strictly anaerobic, and rod shaped, having flagella only on one side of the cell. The main metabolic product was propionic acid. In addition acetic, succinic, and lactic acids and acetoin were formed. Malonate inhibited the production of propionic acid by the strain studied and by both Pectinatus and Propionibacterium strains. The guanine-plus-cytosine content of deoxyribonucleic acid was 36 mol%. Differences between this strain and Pectinatus strains were 2 to 5 percentage points. Immunofluorescent staining and gel diffusion precipitin tests revealed that the antigenic structure differed from those of Pectinatus strains. The isolated organism can, despite some differences, be regarded as belonging to the genus Pectinatus.

Journal Article↗

Peptidases in germinating barley grain: properties, localization and possible functions.

Barley grain contains about 10% insoluble reserve proteins. When the grain germinates the reserve proteins are hydrolysed to amino acids and transported to the growing tissues of the seedling. In the resting grain most of the reserve proteins are 'packed' into the non-living storage tissue, the starchy endosperm. During germination the internal pH of the starchy endosperm is about 5, and it contains high activities of proteinases (secreted by the living aleurone cells) and carboxypeptidases, all with pH optima between 4 and 6. As a whole the starchy endosperm of a germinating grain resembles a giant secondary lysosome. Adjacent to the starchy endosperm is a specialized absorptive and processing tissue, the scutellum. This organ contains very high activities of the 'acid carboxypeptidases' and also two 'alkaline peptidase': a leucine aminopeptidase and a dipeptidase, both pH optima at 8 to 10. The high peptidase activities in the scutellum suggest that the hydrolysis products of the reserve proteins are absorbed from the starchy endosperm as a mixture of amino acids and small peptides, which are hydrolysed to amino acids in the scutellum before transport to the growing seedling tissues.

Aminopeptidases↗