Potato phosphatase

The phosphomonoesterases that proved most useful in this work, although free of proteolytic impurities, were found to be complex in their behavior toward phosphate esters. As indicated in Table II, if tested with the aid of low molecular weight substrates, the intestinal (85) and the potato phosphatase (34) act on 0—P and N—P bonds, whereas the prostate enzyme (86) hydrolyzes only 0—P linkages. After the discovery of the specificity of two of these enzymes for low molecular weight N—P esters, it was noticed that the intestinal enzyme, although classified in the literature as alkaline phosphatase, hydrolyzes N—P bonds both at pH 5.6 and 9.0, but not at pH 7.0. Since the pH range of 5 to 6 is that of maximum stability of almost all proteins, most experiments were carried out in this pH range. Thus the use of these three enzymes, either alone or in combination with each other, proved to be quite a powerful tool. 

If the molecular weights of pepsin and pepsinogen are 35,000 and 38,000, respectively (61), each of these molecules contains one atom of phosphorus (28, 60). Since it had been shown that ovalbumin and a-casein are readily dephosphorylated by certain phosphatases from mammalian tissue, and from potato, the action of these enzymes on pepsin and its precursor w as studied. It was found that only the potato phosphatase at pH 5.6 de-phosphorylates pepsin and pepsinogen, whereas prostate phosphatase does not act on these proteins. The intestinal enzyme, although not active at pH 6.0, liberates phosphorus at pH 8.9 (67). 

Action of Potato Phosphatase on Pepsin and Pepsinogen Each reaction mixture contained 1% protein and 0.003% enzyme in sodium acetate buffer of pH 5.6 and 0.1 r/2. 

Beyond shikimic acid three compounds were detected in culture filtrates that are themselves completely devoid of growth-promoting activity, but which yield growth factors on being autoclaved. One of these was foimd to yield shikimic acid on acid hydrolysis g08). On isolation this compound was identified as being 5-phosphoshikimic acid. The position of the phosphate group was established by exclusion of the other possible positions. The compound is completely hydrolyzed by potato phosphatase to shikimic acid and phosphate. The reason it is not a growth... 

Purple acid phosphatase (PAP) or tartrate-resistant phosphatase is not thought to be a protein phosphatase but it has a very similar dimetallic active site structure to that found in protein phosphatases. PAPs have been identified in bacteria, plants, mammals, and fungi. The molecular weights (animal 35 kDa, plant 55 kDa) are different and they exhibit low sequence homology between kingdoms but the residues involved in coordination of the metal ions are invariant. " There has been considerable debate as to the identity of the metal ions in PAPs in vivo. Sweet potato, Ipomoea batatas, has been shown to possess two different PAP enzymes and the active site of one of them has been shown to contain one Fe and one Zn " " ion. Another report has established that the active site of a PAP from sweet potato contains one Fe " and one Mn +. The well-characterized red kidney bean enzyme and the soybean enzyme contain Fe " and Zn. Claims that PAP from sweet potato has 2Fe ions or 2Mn ions have been discussed elsewhere. One explanation is that these are different forms of the enzyme, another is that because the metal ions are labile and are rapidly incorporated into the active site, the enzyme contains a mixture of metal ions in vivo and the form isolated depends on the conditions of isolation. 

AGIRE computer program for, 249, 79-81, 225-226 comparison to analysis based on rates, 249, 61-63 complex reactions, 249, 75-78 experimental design, 249, 84-85 inhibitor effects, 249, 71-75 potato acid phosphatase product inhibition, 249, 73-74 preliminary fitting, 249, 82-84 prephenate dehydratase product inhibition, 249, 72-73 product inhibition effects, 249, 72-73 prostate acid phosphatase phenyl phosphate hydrolysis, 249, 70 reactions with two substrates, 249, 75-77 reversible reactions, 249, 77-78 with simple Michaelian enzyme, 249, 63-71 [fitting equations, 249, 63] with slow-binding inhibitors, 249, 88 with unstable enzymes, for kinetic characterization, 249, 85-89. 

Acid Phosphatase Potato CTAB/isooctane/chloroform Activity studies [97]... 

Tanemura, Y, Yoshino, M. (2006). Regulatory role of polyamine in the aeid phosphatase from potato tubers. Plant Physiol. Biochem.,44,43 8. 

Some acid phosphatases from animals and plants are violet in color and contain iron (Chapter 16) and an Mn3+-containing acid phosphatase has been isolated from sweet potatoes.720 These enzymes have dimetal centers, often containing one Zn2+ and one Fe3+ with bridging carboxylate and hydroxide ions between the metals. Imidazole, tyrosinate, and carboxylate side chains hold the metals as in Fig. 16-20. A water molecule bound to the Fe3+ is thought to dissociate with a low pKa of 4.8 to give an Fe3+ OH complex. The hydroxyl ion can then attack the phospho groups, one... 

Purple, iron-containing acid phosphatases have been purified from animal sources and from some plant sources.350 However, the purple acid phosphatase from the sweet potato contains manganese, the purple colour arising from an intense absorption band at about 515 nm. There is some doubt over the stoichiometry, in that the dimeric enzyme may contain one351 or two352 Mn2+, apparently depending on the variety of sweet potato. The iron acid phosphatases contain two Fe atoms. 

A number of purple acid phosphatases821 have been isolated from animal sources, including bovine spleen, rat bone and the enamel organ of rat molars. Other phosphatases may belong to this class but the identification is not yet certain. Purple acid phosphatase from the sweet potato, as noted in Section 62.1.3.6.1, contains manganese. 

Acid phosphatase (EC 3.1.3-2) Sigma type III from potato at... 

The isolation of the first manganese-containing acid phosphatase was reported in 1971 from the juice of the sweet potato (Kokei No. 14) (67). The enzyme was unique in that it was distinctly purple, the color resulting from a broad absorption band with a maximum at 555 nm. The enzyme was determined to be 110 kDa, composed of two 55-kDa subunits. The purple enzyme was capable of hydrolyzing a variety of biologically relevant phosphates as well as inorganic pyrophosphate [Eq. (2)]. Emission spectroscopy revealed the presence of Mn (68). 

Similar Mn-containing enzymes were subsequently isolated from other plant sources spinach leaves (71), rice plant cultured cells (72), soybeans (73-75), and the tubers of the sweet potato Kintoki (76-81) (Table III). Sweet potatoes have recently been reported to possess two different acid phosphatases which were immunologically distinct but which have similar molecular weights and metal content (106). Interestingly, sulfhydryl reagents have been shown to inactivate the soybean enzyme (75). 

Presently, the vast majority of information on the Mn site in these acid phosphatases comes from the enzyme from sweet potato tubers. This 110-kDa enzyme is identical to the previously reported sweet potato enzyme likewise, a 55-kDa subunit was found (78). However, the enzyme possesses only one Mn per enzyme molecule. At 293 and 77 K, no EPR signal could be detected for the native enzyme. Inactivation of the enzyme by heat treatment or the addition of acid results in the appearance of a six-line EPR pattern due to aquated Mn(II). As in the case of Mn SODs, this was taken as evidence for Mn(III) in the native... 

The amino acid compositions of the beta-amylase from sweet potato, soya bean, wheat, and malted sorghum have been determined, and are shown in Table XIII. These results may suggest that the beta-amylase from these different sources differs in structure. This is, perhaps, not surprising, but it should be noted that the sorghum amylase contained 9% of pentose, and the important, sulfiir-containing amino acid cysteine was not reported and the soya-bean enzyme still contained traces of aipba-amylase and phosphatase. The sequence of amino acids, or the three-dimensional structure of any... 

Most amylase preparations have a certain phosphatase activity. Some of the preparations used in our experiments were tested on glycerophosphate (Table XXVI) at pH 5.3 and 30°. Parallel experiments with potato starch (Table XXVI) show that the action of the phosphatases on the combined phosphoric acid in starch or limit dextrins, respectively, is very slight compared to the action on glycerophosphate. It is not clear... 

So far, only very little attention has been focussed on the use of zeolites in biocatalysis, i.e., as supports for the immobilization of enzymes. Lie and Molin [116] studied the influence of hydrophobicity (dealuminated mordenite) and hydrophilicity (zeolite NaY) of the support on the adsorption of lipase from Candida cylindracea. The adsorption was achieved by precipitation of the enzyme with acetone. Hydrolysis of triacylglycerols and esterification of fatty acids with glycerol were the reactions studied. It was observed that the nature of the zeolite support has a significant influence on enzyme catalysis. Hydrolysis was blocked on the hydrophobic mordenite, but the esterification reaction was mediated. This reaction was, on the other hand, almost completely suppressed on the hydrophilic faujasite. The adsorption of enzymes on supports was also intensively examined with alkaline phosphatase on bentolite-L clay. The pH of the solution turned out to be very important both for the immobilization and for the activity of the enzyme [117]. Acid phosphatase from potato was immobilized onto zeolite NaX [118]. Also in this study, adsorption conditions were important in causing even multilayer formation of the enzyme on the zeolite. The influence of the cations in the zeolite support was scrutinized as well, and zeolite NaX turned out to be a better adsorbent than LiX orKX. 

If, on the other hand, either the intestinal phosphatase at pH 9.0 or the potato enzyme at pH 5.6 are added to ovalbumin, the reaction is more complex. The protein is rapidly dephosphorylated until 46 % of the phosphorus is released (Fig. 2a). Here, Ai is again converted into a protein with the properties of A2. Dephosphorylation, however, continues and a new component, A3, appears which moves more slowly than A2 and is a phosphorus-free ovalbumin (line 4, Fig. 25). 

Phosphatase, acid Origin potato Roche Diagnostics Phosphatase, acid, grade II... 

Feng, J., Yuan, F., Gao, Y, Liang, C., Xu, )., Zhang, C., He, L. A novel antimicrobial protein isolated from potato [Solanum tuberosum) shares homology with an acid phosphatase. Biochem. J. 2003, 376, 481-487... 

The purple acid phosphatases (PAP) catalyze the hydrolysis of phosphate esters under acidic pH conditions (pH optimum 5) (9, 10). They differ from other acid phosphatases in having a distinct purple color due to the presence of iron or manganese and in being uninhibited by tartrate. Diiron units have been found in the active sites of the enzymes from mammalian spleen (171-173) and uterus (173, 174), while a heterodinu-clear FeZn unit has been characterized for the enzyme from red kidney bean (175). Either the Fe2 or the FeZn unit is catalytically competent in these enzymes, since the enzymes from porcine uterus and bovine spleen can be converted into active FeZn forms and the kidney bean enzyme can be transformed into an active Fe2 form (176). There are also enzymes from other plant sources (particularly sweet potato) that have been reported to have either a mononuclear Mn(III) or Fe(III) active site (177), but these are beyond the scope of the review. This section will focus on the enzymes from porcine uterus (also called uteroferrin), bovine spleen, and red kidney bean. 

Sindelar, L. and O. Makovcova Activity of phosphatases and content of free saccharides in Nicotiana tabacum cv Samsun infected by Potato Y virus Biol. Plant 16 (1974) 376-381. 

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