Isoelectric focusing of membrane proteins from spinach chloroplasts

Synthesis of Thylakoid Membrane Proteins by Chloroplasts Isolated from Spinach

Intact chloroplasts, purified from spinach leaves by sedimentation in density gradients of colloidal silica, incorporate labeled amino acids into at least 16 different polypeptides of the thylakoid membranes, using light as the only source of energy . The thylakoid products of chloroplast translation were visualized by subjecting membranes purified from chloroplasts labeled with [88S]methionine...

Characterization of envelope membrane polypeptides from spinach chloroplasts.

Chloroplast envelope polypeptides from spinach were separated into several fractions on the basis of their solubility in a mixture of chloroform/methanol (2:1, v/v) or in 0.1 N NaOH. Using a simple two dimension procedure for gel electrophoresis, we resolved up to 70 polypeptides. The envelope is characterized by the preponderance of high molecular weight polypeptides (Mr > 54,000), many of...

Isoelectric focusing.

Localization of phosphatidylcholine in outer envelope membrane of spinach chloroplasts

We have examined the effects of phospholipase C from Bacillus cereus on the extent of phospholipid hydrolysis in envelope membrane vesicles and in intact chloroplasts. When isolated envelope vesicles were incubated in presence of phospholipase C, phosphatidylcholine and phosphatidylglycerol, but not phosphatidylinositol, were totally converted into diacylglycerol if they were available to the e...

Isoelectric focusing and crossed immunoelectrophoresis of heme proteins in the Escherichia coli cytoplasmic membrane.

Isoelectric focusing (IEF), agarose electrophoresis, and crossed immunoelectrophoresis (CIE) were used to resolve the heme-containing proteins of the Escherichia coli cytoplasmic membrane after solubilization by Triton X-100. Two bands in IEF stained for heme with pI values of 4.7 and 5.3. One of the bands, with an isoelectric point of pH 5.3, was present only when the cells were grown to late ...