Wheat germ, acid phosphatase

N3-Phosphohistidine has been isolated from an alkaline hydrolysate of liver acid phosphatase (73) while N phosphohistidine has been isolated from prostate, placenta, and wheat germ acid phosphatases (74, 75). ]V3-Phosphohistidine is found in histone H4 (IV, F2al) (76). Phosphohistidines, substituted on either ring nitrogen atom, and c-N-phospholysine were isolated from a purified citrate cleavage enzyme (77). There is a good possibility that certain acidic nuclear proteins may contain e-iV-phospholysine and w-N-phosphoarginine (78). e-N-Phospholysine is present in histone I (FI) (78a). Phosphothreonine is found in certain proteins of which phosvitin is an example (79,80). 

Digestion with snake venom phosphodiesterase, wheat germ acid phosphatase, ans beef spleen phosphodiesterase are almost extended to 77 83%, 97 99%, and 77 80%, respectively. Further no evidence was found for the presence of oligonucleotides linked through the heterocyclic base. 

Purification of Acid Phosphatase from Wheat Germ... 

Figure 10-17. Schematic flow chart describing the major steps in the partial purification of acid phosphatase from wheat germ.

At present, little is known about the phosphatidate phosphohydrolase step in the biosynthetic pathway to triacylglycerols. The enzyme was specifically measured by Moore et al, (1973) in subcellular fractions of castor bean endosperm and found to be located mainly in the endoplasmic reticulum, with some activity in the soluble fraction. In leaves, the highest specific activity was found in an undefined particulate fraction, whereas the m or part of the activity was soluble (Heinz, 1977). Other evidence for a specific phosphatidate phosphohydrolase activity in chloroplast membranes was indirect (Joyard and Douce, 1977). Care must always be taken to ensure that the activity is not due to a nonspecific phosphatase in view of the report by Blank and Snyder (1970) that wheat germ contains an acid phosphatase capable of dephosphorylating phosphatidic acid. The enzyme described by Moore et al. 

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