Tolerance of Corn (Zea mays) Lines to Clomazone

Corn hybrids and inbreds were ranked for their relative tolerance to soil-incorporated clomazone, as assessed by the level of discoloration injury in the greenhouse. Inbred W117 was the most tolerant corn line tested. Some corn lines were affected similarly by clomazone. Inbred A619 was in the most susceptible group. Clomazone injury to A619 (susceptible) and W117 (tolerant) corn was similar when the clomazone rate was 10-fold greater on W117 than on A619. The distribution of corn lines on a sensitivity scale was of limited range; the distribution of hybrids on this scale was a single symmetrical peak. Changing the growth temperature or soil composition would change the absolute level of corn injury caused by a rate of clomazone but did not change the relative ranking of the corn lines in the test. A subset of the greenhouse-tested corn lines also was evaluated in several field locations. The tolerance of corn in a given field was highly (P<0.005) correlated with tolerance in the greenhouse; however, the absolute levels of injury differed among locations. The tolerance of- hybrids of known pedigree was highly (P<0.0002) correlated with the tolerance of the parent inbreds, indicating this trait was inherited.

Structural studies on the major component of Gladiolus style mucilage, an arabinogalactan-protein

The major component of the Gladiolus style mucilage was shown to be an arabinogalactan-protein. The arabinogalactan-protein was isolated from the style extract by affinity chromatography with tridacnin (the galactose-binding lectin from the clam Tridacna maxima) coupled to Sepharose 4B. The isolated arabinogalactan-protein represents 40% of the soluble style extract; it contains 90% (w/w) carbohydrate and 3% protein. The major monosaccharides of the carbohydrate component are galactose and arabinose, in the proportions 6:1. A component with a similar composition was also isolated from the crude extract by precipitation with the beta-glucosyl artifical carbohydrate antigen. The protein moiety of the arabinogalactan-protein remained associated with the carbohydrate after chromatography in urea, and has high contents of serine, glutamic acid, aspartic acid, glycine and alanine. The arabinogalactan-protein is apparently chemically homogeneous; it eluted as a single symmetrical peak from Sepharose 4B, and three fractions collected across the peak were structurally similar. Ultracentrifugal studies showed it to be polydisperse in the mol.wt. range 150 000–400 000. The information obtained from methylation analyses, oxalic acid and enzymic hydrolyses is consistent with a model having a beta 1 leads to 3 galactan backbone, branched through C(O)6 to beta 1 leads to 6 galactan side chains. The arabinose is exclusively present as terminal alpha-L-arabinofuranosyl residues. Enzymic removal of the arabinose residues resulted in a marked decrease in solubility of the molecule. The localization of the arabinogalactan-protein in the mucilage of the style canal was demonstrated cytochemically. The possible roles of the arabinogalactan-protein in relation to recognition of compatible pollen and pollen-tube growth are discussed.

Purification of Staphylocoagulase by a Bovine Prothrombin-Sepharose 4B Column and its Physicochemical Properties

Staphylocoagulase is known to coagulate human plasma, but not bovine’s, by forming an active molecular complex with prothrombin. However, there is no enough knowledges in respect to the molecular mechanism of prothrombin activation with staphylocoasulase. A new simplified method was developed for the large-scale purification of coagulase from culture filtrates of Staphylococcus aureus. strain st-213, using Sepharose AB covalently linked with bovine prothrombin. This affinity column adsorbed strongly the coagulase, which was eluted with 1.0 M NaSCN. The yield of coagulase activity was in the range of 75 to 85X, The purified coagulase showed a single symmetrical peak by ultracentrifugal analysis (S20,w=6.47), and it gave a single precipitin line against anti-purifled staphylocoagulase serum, as revealed by the immunodiffusion test. However, the preparation was shown to contain three active components by the isoelectric foccusing method, suggesting some microheterogeneity. The molecular weight estimated by SDS-gel electrophoresis was 71,000 (major material). No cystine residue was found in the purified material and its NH2-terminal sequence was Ile-Ile-. It is of interest that staphylocoagulase interacts strongly with bovine prothrombin-Sepharose AB, whereas it does not form any active complex with the prothrombin, unlike human prothrombin.

SEPHADEX GEL FILTRATION ANALYSIS OF IMMUNOREACTIVE THYROTROPHIC HORMONE IN HUMAN URINE

SUMMARY To assess whether urinary immunoassayable thyroid-stimulating hormone (TSH) differed from pituitary and serum TSH, urinary concentrates from two hypothyroid subjects were analysed by Sephadex G-100 gel filtration. The elution profiles, measured by radioimmunoassay, were then compared with those of neat sera from hypothyroid patients and human pituitary TSH preparations. The pituitary preparations and the hypothyroid serum were eluted as a comparable single symmetrical peak corresponding to that obtained from a highly purified radio-iodinated human TSH of pituitary origin; no evidence of 'big' TSH emerged. In contrast, however, the material eluted from the hypothyroid urine concentrates not only revealed an asymmetrical peak corresponding to that described above but several other minor peaks eluting later and probably corresponding to fragments of TSH. When human pituitary TSH was infused into two normal subjects, gel filtration analysis of concentrates from urinary samples obtained during and at fixed periods after the infusion revealed a single peak during the infusion but more peaks appeared with the later samples.

NEUTRAL EXTRACELLULAR GLUCAN OF PULLULARIA PULLULANS (DE BARY) BERKHOUT

A neutral extracellular glucan ([α]D23 + 189°) was produced in 12% yield by Pullularia pullulans (de Bary) Berkhout grown on a glucose substrate. A single symmetrical peak on free-boundary electrophoresis in borate and acetate buffers was evidence of homogeneity. Infrared spectroscopy showed that the predominant glucoside linkages were α(1 → 4) and α(1 → 6) with a small proportion of α(1 → 3). Graded acid hydrolysis under conditions of minimum reversion yields glucose, maltose, isomaltose, nigerose, panose, and isomaltotriose. In addition, a trisaccharide, O-α-D-glucopyranosyl-(1 → 4)-O-α-D-glucopyranosyl-(1 → 6)-D-glucopyranose, was isolated. Another trisaccharide was isolated and tentatively identified as O-α-D-glucopyranosyl-(1 → 4)-O-[α-D-glucopyranosyl-(1 → 6)]-D-glucose and hence a small degree of branching may occur in the molecule. The present study has confirmed previous observations that the main linkages are α(1 → 4) and α (1 → 6) and has provided unequivocal proof of the presence of α (1 → 3) linkages. Periodate oxidation studies confirmed the foregoing structural features and showed that the glucan was linked α(1 → 4), 65%; α(1 → 6), 29%; and α(1 → 3), 6%.

FURTHER STUDIES ON THE PURIFICATION OF THROMBIN

Purified biothrombin (bovine) was fractionated with the use of amberlite IRC-50 columns to obtain resin thrombin with an activity of 4100 units/mg. dry weight or 45,000 units/mg. tyrosine. As obtained from a resin column in 0.3 M phosphate buffer, pH 8.0, the thrombin is stable for 5 days at room temperature. At 4 °C. about 70% of the activity remains after 20 weeks. The maximum molecular weight is estimated by comparing with the specific activity (2000 units/mg.) and molecular weight (62,700) of purified prothrombin as follows: 2000/4100 × 62,700 or 30,600 as the probable molecular weight. Resin thrombin can lose its fibrinogen-clotting power while esterase activity is retained. On the other hand the esterase activity can be depressed without diminishing the clotting activity. Resin thrombin lyses fibrin. When examined in an ultracentrifuge a single symmetrical peak was found with a sedimentation constant of S = 3.9 (20 °C., 0.1 M KCl, 5.5 mg./ml.) Citrate thrombin was also fractionated with the use of IRC-50 to obtain material with a specific activity of 47,000 units/mg. tyrosine.

FURTHER STUDIES ON THE PURIFICATION OF THROMBIN

Purified biothrombin (bovine) was fractionated with the use of amberlite IRC-50 columns to obtain resin thrombin with an activity of 4100 units/mg. dry weight or 45,000 units/mg. tyrosine. As obtained from a resin column in 0.3 M phosphate buffer, pH 8.0, the thrombin is stable for 5 days at room temperature. At 4 °C. about 70% of the activity remains after 20 weeks. The maximum molecular weight is estimated by comparing with the specific activity (2000 units/mg.) and molecular weight (62,700) of purified prothrombin as follows: 2000/4100 × 62,700 or 30,600 as the probable molecular weight. Resin thrombin can lose its fibrinogen-clotting power while esterase activity is retained. On the other hand the esterase activity can be depressed without diminishing the clotting activity. Resin thrombin lyses fibrin. When examined in an ultracentrifuge a single symmetrical peak was found with a sedimentation constant of S = 3.9 (20 °C., 0.1 M KCl, 5.5 mg./ml.) Citrate thrombin was also fractionated with the use of IRC-50 to obtain material with a specific activity of 47,000 units/mg. tyrosine.