The invertase complement of cold-hardy and cold-sensitive wheat leaves

1975 ◽  
Vol 53 (13) ◽  
pp. 1333-1337 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Triticum Aestivum L ◽  
Cold Hardening ◽  
High Molecular Weight Form ◽  
Different Temperatures ◽  
Cold Sensitive ◽  
Wheat Leaves ◽  
Cold Hardy ◽  
Molecular Weight Form

The invertase (EC 3.2.1.26) of leaves from two cultivars of wheat (Triticum aestivum L. emend Thell. ssp. vulgare), Rescue (cold-sensitive) and Kharkov 22 MC (cold-hardy), grown at 20 °C (non-hardening conditions) and at 4–6 °C (cold-hardening conditions), has been separated into three different forms by gel filtration. In Rescue wheat, the complement of different forms of invertase from the leaves did not change greatly when the plants were grown at different temperatures. In Kharkov 22 MC grown at 20 °C, the quantity of the medium-molecular-weight form of invertase was much greater than that of the high-molecular-weight form of invertase; however, when this variety was grown at 4–6 °C, the relative quantities of these two forms of invertase were reversed. This change in the ratio of the different forms of invertase in the leaves appears to be associated with the process of cold-hardening.

Changes in the proportions of two forms of invertase associated with the cold acclimation of wheat

1979 ◽  
Vol 57 (4) ◽  
pp. 413-419 ◽  
Author(s):  
D. W. A. Roberts
Keyword(s):  
Cold Hardiness ◽  
Cold Resistance ◽  
Rank Order ◽  
Triticum Aestivum L ◽  
Cold Hardening ◽  
Wheat Varieties ◽  
Cold Sensitive ◽  
Wheat Leaves ◽  
Triticum Durum Desf ◽  
Winter Wheat Varieties

The proportion of two of the forms of invertase in wheat leaves is different when the plants are grown under cold-hardening conditions compared with under nonhardening conditions. Twelve varieties of bread wheat (Triticum aestivum L. emend. Thell. ssp. vulgare) of diverse levels of cold hardiness showed a high rank-order correlation between their level of cold hardiness and the ratio of peak I to peak II invertase in the leaves grown for 7–8 weeks at 6–4 °C. Similar trends were evident among four of these varieties grown for 11–13 or 20–24 weeks at 3 °C. No such correlations were observed in plants grown at 21 °C, i.e., under conditions that induce little or no cold hardening. The single durum wheat (Triticum durum Desf.) tested behaved somewhat differently.When plants of a single variety were grown under different hardening conditions, the cold resistance of the plants and the ratio of peak I to peak II invertase in their leaves were not closely related. However, cold-hardened common winter wheat varieties had much higher ratios of peak I to peak II invertase in their leaves than did similar varieties in the unhardy condition or cold-sensitive varieties.In the bread wheats, the amount of peak I invertase increases in plants grown under conditions causing cold hardening relative to that in plants grown at 21 °C while the amount of peak II invertase decreases. This suggests that one form of invertase replaces another during cold hardening.

Plasma pattern of immunoreactive ACTH in normal man and in patients with Nelson's syndrome

1981 ◽  
Vol 96 (1) ◽  
pp. 15-23 ◽  
Author(s):  
M. Thorén ◽  
M. Ajne ◽  
K. Hall
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gel Filtration ◽  
Nelson’S Syndrome ◽  
Nelson's Syndrome ◽  
High Molecular Weight Form ◽  
Normal Individuals ◽  
Normal Man ◽  
The Difference ◽  
Molecular Weight Form

Abstract. A radioimmunoassay for ACTH determinations in human plasma was developed using an N-terminal antiserum. Plasma ACTH levels at 6 a.m. in 39 patients with normal pituitary-adrenal function were below 4 pmol/l in two individuals. The remaining had a mean of 32.7 ± 4 pmol/l (n = 37). Gel filtration on Sephadex G-50 medium and G-75 revealed that a high molecular weight immunoreactive ACTH was found in plasma from both normal individuals and patients with Nelson's syndrome. The stimulation of ACTH secretion with metyrapone (750 mg perorally) significantly increased the mean plasma levels of 1–39 ACTH after 3 h (from 0.9 to 6.6 pmol/l) in 10 healthy individuals. The level of the high molecular weight form remained constant. In one patient with Nelson's syndrome hydrocortisone iv (100 mg/h for 3 h) suppressed the total ACTH levels from 360 to 83 pmol/l following corticoid withdrawal on the previous evening, but did not affect the high molecular weight form of ACTH. The difference between the amounts of immunoreactive ACTH found in plasma from normal individuals and from patients with Nelson's syndrome was attributed to 1–39 ACTH.

Spreading of microinjected horseradish peroxidase to nondescendant cells in embryos of Patella (Mollusca, Gastropoda)

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 713-722
Author(s):  
W.M. Kuhtreiber ◽  
F. Serras ◽  
J.A.M. van den Biggelaar
Keyword(s):  
Molecular Weight ◽  
Stem Cell ◽  
Horseradish Peroxidase ◽  
High Molecular Weight ◽  
Fluorescein Isothiocyanate ◽  
Contact Phase ◽  
High Molecular Weight Form ◽  
Contact Stage ◽  
Fluorescein Isothiocyanate Dextran ◽  
Molecular Weight Form

We have injected horseradish peroxidase (HRP) and fluorescein-isothiocyanate dextran (FD) into cells and into the blastocoelic cavity of Patella vulgata embryos, before and during the interval between 5th and 6th cleavage, in which the mesodermal stem cell is determined by means of interactions between the central 3D macromere and the contacting animal micromeres. Intracellular injections of HRP at different stages showed that, whereas before this contact phase no spreading of label was observed, a clear intercellular transfer of HRP was found after the contact was established. Control experiments showed that it was HRP in its intact, high molecular weight form that was transferred in the living embryo. Injections of HRP into the blastocoelic cavity gave essentially the same results. In these cases, the HRP was taken up by the cells from contact stage onwards. When FD was injected into the blastocoelic cavity, no uptake was observed, not even after prolonged presence of FD in it. However, when HRP and FD were mixed, both were taken up, starting at contact stage. Differences in labelling pattern of HRP, as compared with FD, and a shift of the FD fluorescence after uptake, suggest that receptor-mediated endocytosis is involved. The possible morphogenetic significance of the transfer mechanism is discussed.

scholarly journals High Molecular Weight Factor VIII Coagulant Activity in Cryoprecipitate and Polyethylene Glycol Precipitates

1977 ◽  
Author(s):  
K. A. Rickard ◽  
T. Exner ◽  
H. Kronenberg
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Factor Viii ◽  
High Molecular Weight ◽  
Gel Filtration ◽  
Lower Molecular Weight ◽  
Human Antibody ◽  
High Molecular Weight Material ◽  
Coagulant Activity ◽  
Molecular Weight Form

Gel filtration of human plasma cryoprecipitate on Sepharose 2B indicated the molecular weight of factor VIII coagulant activity (VIIIc) to be significantly greater than that found in antihaemophilic concentrate. Polyethylene glycol at 3% concentration precipitated approximately half of the VIIIc from cryoprecipitate. This activity eluted as high molecular weight material on gel filtration. The addition of more polyethylene glycol to a concentration of 8% precipitated most of the remaining VIIIc from cryoprecipitate. This activity appeared to be of significantly lower molecular weight, approximately corresponding in elution volume to that observed for antihaemophilic concentrate. The possibility that an antibody to VIIIc generated in a patient treated with cryoprecipitate might be directed against the higher molecular weight form of factor VIII was investigated. However, no significant differences between the higher and lower molecular weight forms of factor VIII either in stability or in reactivity with human antibody to factor VIII were found.

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