Acid phosphatase types

LI. Lai, L. Y. Hereditary red cell acid phosphatase types in Australian White and New Guinea native populations. Acta Genet. Statist. Med. 16, 313-320 (1966). 

L3. Lamm, L. U., Family studies of red cell acid phosphatase types. Hum. Hered. 20, 329-335 (1970). 

Kai M, Wada I, Imai S, Sakane F, Kanoh H (1996) Identification and cDNA cloning of 35-kDa phosphatidic acid phosphatase (type 2) bound to plasma membranes. Polymerase chain reaction amplification of mouse H2O2-inducible hic53 clone yielded the cDNA encoding phosphatidic acid phosphatase. J Biol Chem 271 18931-18938... 

Phosphatases are numerous and important enzymes (see also Chapt. 2). They are classified as phosphoric monoester hydrolases (phosphatases, EC 3.1.3), phosphoric diester hydrolases (phosphodiesterases, EC 3.1.4), triphosphoric monoester hydrolases (EC 3.1.5), diphosphoric monoester hydrolases (pyrophosphatases, EC 3.1.7), and phosphoric triester hydrolases (EC 3.1.8) [21] [63]. Most of these enzymes have a narrow substrate specificity restricted to endogenous compounds. However, some of these enzymes are active toward xenobiotic organophosphorus compounds, e.g., alkaline phosphatase (EC 3.1.3.1), acid phosphatase (EC 3.1.3.2), aryldialkylphosphatase (para-oxonase (PON1), EC 3.1.8.1) and diisopropyl-fluorophosphatase (tabunase, somanase, EC 3.1.8.2) [64 - 70]. However, such a classification is far from definitive and will evolve with further biochemical findings. Thus, a good correlation has been found in human blood samples between somanase and sarinase activities on the one hand, and paraoxonase (PON1) type Q isozyme concentrations on the other [71]. 

The lysosomes are the cell s stomach, serving to break down various cell components. For this purpose, they contain some 40 different types of hydrolases, which are capable of breaking down every type of macromolecule. The marker enzyme of lysosomes is acid phosphatase. The pH optimum of lysosomal enzymes is adjusted to the acid pH value and is also in the range of pH 5. At neutral pH, as in the cytoplasm, lysosomal enzymes only have low levels of activity. This appears to be a mechanism for protecting the cells from digesting themselves in case lysosomal enzymes enter the cytoplasm at any time. In plants and fungi, the cell vacuoles (see p. 43) have the function of lysosomes. 

The most clearly documented role lor selenium is as a necessary component of glutathione peroxidase. Selenium is also involved in the functions of additional enzymes, e.g.. type I iodoihvronine deiodinase. leukocyte acid phosphatase, and glucuronidases. A role for selenium in electron transfer has been suggested as has involvement in nonheme iron proteins. Selenium and vitamin b appear to be necessary lor proper functioning of lysosomal membranes. A role for selenium in metabolism of thyroid hormone has been continued. 

Scott (80) purified red cell acid phosphatase of homozygous types A and B by using ammonium sulfate and DEAE-cellulose chromatography. The relative activity of these isozyme preparations was the same when tested with a number of substrates. Type B enzyme showed small kinetic... 

In addition to differences in electrophoretic mobility between the various heritable types of red cell acid phosphatase, there are striking quantitative differences. Figure 13 (86) demonstrates that the mean level of enzymic activity of type B acid phosphatase is considerably greater than the mean level of type A. Type BA lies almost exactly between the two curves. The genetic relationships of the human isoenzymes have been reviewed by Giblett (79). 

An acid phosphatase from the mycelium of the fungus Neurospora crassa has been purified 1400-fold with a 40% recovery. The pH maximum is 5.6 with j3-glycerophosphate as substrate. Fluoride and D-(-f-)-tartrate are competitive inhibitors so that this enzyme fits into a rather general pattern for others of its type which have been described (116). 

At least four acid phosphatase fractions have been obtained by ammonium sulfate, DEAE hydroxylapatite, and electrophoretic separation. One type of activity, nucleoside 2 - or 3 -phosphatase was purified 1500-fold. Hexosephosphatase activity was also obtained in three separate fractions. All three fractions were different with respect to rate of splitting of different substrates and pH optimum (118). 

MacIntyre and Dean (119) report that acid phosphatase from D. melanogaster has slow and fast electrophoretic variants specified by co-dominant alleles. Thus, acid phosphatases AA, BB, and AB were studied. Types AA and BB could be inactivated by exposure to acid. Reactivation of enzymic activity could be accomplished by dialysis against buffers at pH 6.5. Mixtures of AA and BB produced some AB reconstituted enzyme. From this evidence it seems very probable that acid phosphatase, at least in this species, consists of at least two polypeptide chains. 

Blood Alkaline phosphatase (bone-specific) Osteocalcin Procollagen type I carboxy-terminal propeptide (PICP) Procollagen type I amino-terminal propeptide (PINP) Procollagen type III amino-terminal propeptide (PIIINP) Blood Acid phosphatase (acid-resistant) Type I collagen carboxy-terminal telopeptide (ICTP) Urine Calcium Hydroxyproline Cross-linked peptides (pyridinium and deoxypyridinoline)... 

Takayama TK, McMullen BA, Nelson PS, Matsumura M, Fujikawa K. Characterization of hK4 (Prostase), a prostate-specific serine protease Activation of the precursor of prostate specific antigen (pro-PSA) and single-chain urokinase-type plasminogen activator and degradation of prostatic acid phosphatase. Biochemistry 2001 40 15341-15348. 

The enzymes used to generate reactive quinone methides often undergo inactivation by addition of this electrophile to essential nucleophilic amino acid side chains of the protein catalyst. This is a type of suicide enzyme inhibition.80 This was observed for the acid phosphatase and ribonuclease catalysts used to generate 43.76 79 Alkaline phosphatase has been used to remove the phosphate protecting group from a derivative of an o-difluoromethyl phenyl phosphate that was covalently attached to a solid support. Breakdown of the immobilized 4-hydroxybenzyl difluoride gives an immobilized quinone methide that, in principle, will react irreversibly with proteins and lead to their attachment to the solid support.81... 

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

Interestingly, there is a close structural correspondence between the active sites of the haloperoxidases and the acid phosphatases that allows both peroxidase and phosphatase activity from the two types of enzymes [49-51], For instance, recombinant acid phosphatases from both Shigella flexneri and Salmonella enterica ser. typhimurium, when substituted by vanadate, are able to oxidize bromide when in the presence of hydrogen peroxide. However, the turnover rate is quite slow, which is in accord with the phosphatase active sites not being optimized for peroxidase activity [52],... 

The active sites of these enzymes can have a nitrogen ligand, usually as histidine (acid phosphatases and some protein phosphatases), a nucleophilic serine residue (alkaline phosphatases), a cysteine residue in which the thiol group can form a covalent species with the phosphate ester (protein phosphatases), or an aspartate-linked phosphate (plasma membrane ion pumps). The inhibitory form of vanadium is usually anionic vanadate V(V), but cationic vanadyl V(IV) has also shown strong inhibition of some types of phosphorylase reactions. Above neutral pH, speciation of vanadyl ions produces anionic V(IV) species capable of inhibition of enzymes in the traditional transition-state analogue manner [5],... 

CB - 6%. Erythrocytic acid phosphatase has been found to remain viable for many months after drying and successful typing can be performed on a minimum of several threads (9), (Figure 2). 

Forensic biochemists perform blood typing and enzyme tests on body fluids in cases involving assault, and also in paternity cases. Even tiny samples of blood, saliva, or semen may be separated by electrophoresis and subjected to enzymatic analysis. In the case of rape, traces of semen found on clothing or on the person become important evidence the composition of semen varies from person to person. Some individuals excrete enzymes such as acid phosphatase and other proteins that are seldom found outside seminal fluid, and these chemical substances are characteristic of their semen samples. The presence of semen may be shown by the microscopic analysis for the presence of spermatozoa or by a positive test for prostate specific antigen. 

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