Subcellular location and identification of a large molecular weight substrate for the liver plasma membrane transglutaminase.

Plasma membrane and nuclear fractions have been prepared from mature goose erythrocytes. Examination of the nonhistone protein of the nuclear fraction by sodium dodecyl sulphate – polyacrylamide gel electrophoresis reveals a limited number of molecular weight species some of which are peculiar to the nuclear fraction.Electrophoretic comparison of the goose plasma membrane proteins with those of the human erythrocyte reveals many similarities. In particular, three large molecular weight species occur in both cells. Their function appears to predate the evolutionary loss of the nucleus.

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Liver plasma membrane: The source of high molecular weight alkaline phosphatase in human serum

Hepatology ◽

10.1002/hep.1840050124 ◽

1985 ◽

Vol 5 (1) ◽

pp. 118-128 ◽

Cited By ~ 53

Author(s):

Marc E. De Broe ◽

Frank Roels ◽

Etienne J. Nouwen ◽

Lutgarde Claeys ◽

Roger J. Wieme

Keyword(s):

Molecular Weight ◽

Alkaline Phosphatase ◽

Plasma Membrane ◽

Human Serum ◽

High Molecular Weight ◽

Liver Plasma Membrane

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The External Shape of Human γ GI Immunoglobulin from Crystal Sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010006619x ◽

1971 ◽

Vol 29 ◽

pp. 428-429

Author(s):

L. W. Labaw

Keyword(s):

Molecular Weight ◽

Sodium Phosphate ◽

Osmium Tetroxide ◽

Unit Cell ◽

Monoclinic Space Group ◽

X Ray ◽

Large Molecular Weight ◽

Cell Dimensions ◽

Unit Cell Dimensions ◽

Crystallographic Axes

Crystals of a human γGl immunoglobulin have the external morphology of diamond shaped prisms. X-ray studies have shown them to be monoclinic, space group C2, with 2 molecules per unit cell. The unit cell dimensions are a = 194.1, b = 91.7, c = 51.6Å, 8 = 102°. The relatively large molecular weight of 151,000 and these unit cell dimensions made this a promising crystal to study in the EM.Crystals similar to those used in the x-ray studies were fixed at 5°C for three weeks in a solution of mother liquor containing 5 x 10-5M sodium phosphate, pH 7.0, and 0.03% glutaraldehyde. They were postfixed with 1% osmium tetroxide for 15 min. and embedded in Maraglas the usual way. Sections were cut perpendicular to the three crystallographic axes. Such a section cut with its plane perpendicular to the z direction is shown in Fig. 1.This projection of the crystal in the z direction shows periodicities in at least four different directions but these are only seen clearly by sighting obliquely along the micrograph.

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Exterior and Interior Events in Early Stage of Thrombin-induced Platelet Aggregation

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651878 ◽

1977 ◽

Vol 38 (03) ◽

pp. 0630-0639 ◽

Cited By ~ 4

Author(s):

Shuichi Hashimoto ◽

Sachiko Shibata ◽

Bonro Kobayashi

Keyword(s):

Molecular Weight ◽

Enzyme Activity ◽

Plasma Membrane ◽

Platelet Aggregation ◽

Early Stage ◽

Adenyl Cyclase ◽

Cellular Component ◽

Primary Event ◽

Rabbit Platelets ◽

Membrane Bound

SummaryTreatment of washed rabbit platelets with 1 u/ml of thrombin at 37° C resulted in a disappearance from platelets of a protein with 250,000 dalton molecular weight which was shown to be originated from plasma membrane. Parallel loss of adenyl cyclase was noted, and both reactions were complete within 30 sec. From the patterns of disc electrophoretograms, the importance of quick suppression of thrombin action in demonstrating the primary event was stressed.Thrombin induced an apparent activation of membrane bound phosphodiesterase. This reaction was also complete within 30 sec. The cellular component which contained the enzyme activity was distinct from plasma membrane. Soluble phosphodiesterase was not influenced by thrombin at all.These reactions required intact platelet cells to react with thrombin, and no reaction was detected when subcellular preparations were treated with thrombin.Possibility of collaboration of changes in externally located synthetic enzyme with those in internally located degrading enzyme in the early phase of thrombin action on platelets was suggested.

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