ACP1 and human adaptability 1. Association with common diseases: a case-control study

Human red cell acid phosphatase (ACP1) is a polymorphic enzyme closely related to cytosolic low molecular weight acid phosphatases, a protein family broadly conserved among eukaryotes. Two different functions have been proposed for ACP1: flavin mononucleotide (FMN) phosphatase and phosphotyrosine phosphatase (PTPase). Given that genetic variants of ACP1 activity are common, the enzyme could have a role in regulating a large spectrum of cellular functions and, in turn, disease susceptibility. In the present paper we report a study of ACP1 genetic polymorphism in 1088 normal subjects and in 1267 subjects from the population of Rome admitted to hospital for a number of common diseases. All ACP1 parameters investigated show highly significant differences among samples, suggesting that the enzyme may have a significant role in some of the diseases considered. In particular, consistent associations of ACP1 with developmental disturbances and with hemolytic favism have been observed. In the majority of diseases showing association with ACP1, only one of the two ACP1 isoforms, f and s, is involved, supporting the hypothesis of a functional differentiation between the two enzymatic fractions.     

Red cell acid phosphatase: another polymorphism correlated with Malaria?

The frequency of PC allele for acid phosphatase in fourteen Sardinian villages correlates positively with the altitude and negatively with past malarial morbidity and GdMed prevalence. The susceptibility towards hemolytic favism in Sardinian males with G6PD deficiency is dependent on the erythrocyte acid phosphatase and thalassemia phenotypes. Thalassemia trait exerts a protective action only in subjects carrying PA allele for acid phosphatase. The data suggest that the gradient for malaria morbidity directly or indirectly, through interactions with thalassemia and G6PD polymorphisms, mediated by the habit of eating Vecia faba, may have had a significant role in determining the heterogeneous distribution of acid phosphatase polymorphism in Sardinia. Besides malaria, other environmental factors related with altitude seem to have been very important in shaping the present pattern of distribution of both acid phosphatase and G6PD polymorphisms in Sardinia.     

ACP1GUA-1--a low-activity variant of human erythrocyte acid phosphatase: association with increased glutathione reductase activity.

ACP1GUA-1, a variant of human erythrocyte acid phosphatase, exists as a polymorphism (allele frequency of .132) in the Guaymi Indians of Central America. This variant has an electrophoretic mobility similar to the common B- and C-type variants, but individuals of the ACP1GUA-1 phenotype have a level of enzyme activity only 27% of the activity expected for the ACP1C variant. The GUA-1 variant is more thermostable than is the B variant, and the order of responsiveness to the modulation of activity by purine analogs and folate is always (B)-(A)-(GUA-1). Thus, the GUA-1 variant is a low-activity variant with C-like regulatory properties. Erythrocytes from individuals of the ACP1GUA-1 phenotype have increased basal levels of glutathione reductase, and a larger fraction of the glutathione reductase protein is present as the holoenzyme, indicating increased levels of flavin adenine dinucleotide in the erythrocytes of these individuals. This is consistent with the suggestion that ACP1 has a physiological function as a flavin mononucleotide phosphatase.     

Enzyme polymorphism and clinical variability of diseases: study of acid phosphatase locus 1 (ACP1) in obese subjects

The ACP1*A allele of erythrocyte acid phosphatase (ACP1) has a lower enzymatic activity when compared to other ACP1 alleles and is associated with maximal rate of body growth during intrauterine life. In three different samples of obese subjects (total number = 218). ACP1*A was associated with extreme body mass deviations. No difference in ACP1 allele distribution was observed between obese and nonobese subjects. These data suggest that a genetically determined variability of ACP1 influences the degree of obesity, but only when obesity itself has been triggered by some other factors.     

Nitrite toxicity in Indian major carps: sublethal effect on selected enzymes in fingerlings of Catla catla, Labeo rohita and Cirrhinus mrigala

The effects of 96-h sublethal exposure of nitrite (1, 2, 4, 8 and 10.4 mg l(-1)) on selected enzymatic activities in serum and tissues of fingerlings of catla (Catla catla), rohu (Labeo rohita) and mrigal (Cirrhinus mrigala) were studied for the first time in these species. All three species responded almost identically to nitrite exposure. With increasing nitrite concentration, reduction in activities was observed in acetylcholinesterase (AChE) in brain and liver; alkaline phosphatase (ALP) in serum, brain and gill; and acid phosphatase (ACP) in gill, while progressive increase in alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) activities in brain, gill and serum, and ACP activity in serum and brain was observed. Lactate dehydrogenase (LDH) activity increased in gill, liver, kidney, brain and serum of all three species with increasing nitrite concentration up to 8 mg l(-1) followed by reduction at 10.4 mg l(-1). The study revealed nitrite stress causing alteration in activities of all measured tissue and serum enzymes in the fingerlings, and so stresses the need for proper management of this particular nutrient in water during carp culture.     

Properties of an acid phosphatase from Legionella micdadei which blocks superoxide anion production by human neutrophils

The high-speed supernatant (100,000 g, 1 h) obtained after centrifuging a suspension of Legionella micdadei that had been freeze-thawed and sonicated contained (i) considerable acid phosphatase activity when assayed using 4-methylumbelliferyl phosphate (MUP) as the substrate, and a factor that blocked superoxide anion production by human neutrophils stimulated with f-Met-Leu-Phe. Chromatography of the extract on a hydroxylapatite column resolved two acids phosphatases (designated ACP1 and ACP2). Subsequent chromatography of ACP2 on a Sephadex G-150 column revealed coincident elution of phosphatase activity and neutrophil blocking activity. When heated at 45 degrees C for various periods of time, the phosphatase activity of the acid phosphatase preparation was lost at the same rate as the ability of the preparation to block superoxide anion production by neutrophils. Furthermore, preincubation of neutrophils and acid phosphatase together in the presence of a heteropolymolybdate complex that inhibits the phosphatase eliminated the effect of the L. micdadei phosphatase on neutrophil superoxide anion production. ACP2 had the following properties: pH optimum, 6.0; Km for MUP, 3.8 mM; isoelectric point, 4.5; substrate specificity, MUP greater than ADP greater than phosphoenolpyruvate greater than phosphothreonine greater than phosphoserine greater than phosphotyrosine; molecular weight (estimated by sucrose density gradient centrifugation and gel filtration chromatography), 71,000-86,000. These results indicate that a cell-associated phosphatase may play a role in the virulence of L. micdadei.     

Mechanism of glucose-6-phosphate dehydrogenase-mediated regulation of coronary artery contractility

We previously identified glucose-6-phosphate dehydrogenase (G6PD) as a regulator of vascular smooth muscle contraction. In this study, we tested our hypothesis that G6PD activated by KCl via a phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-protein kinase C (PKC) pathway increases vascular smooth muscle contraction and that inhibition of G6PD relaxes smooth muscle by decreasing intracellular Ca(2+) ([Ca(2+)](i)) and Ca(2+) sensitivity to the myofilament. Here we show that G6PD is activated by membrane depolarization via PKC and PTEN pathway and that G6PD inhibition decreases intracellular free calcium ([Ca(2+)](i)) in vascular smooth muscle cells and thus arterial contractility. In bovine coronary artery (CA), KCl (30 mmol/l) increased PKC activity and doubled G6PD V(max) without affecting K(m). KCl-induced PKC and G6PD activation was inhibited by bisperoxo(pyridine-2-carboxyl)oxovanadate (Bpv; 10 μmol/l), a PTEN inhibitor, which also inhibited (P < 0.05) KCl-induced CA contraction. The G6PD blockers 6-aminonicotinamide (6AN; 1 mmol/l) and epiandrosterone (EPI; 100 μmol/l) inhibited KCl-induced increases in G6PD activity, [Ca(2+)](i), Ca(2+)-dependent myosin light chain (MLC) phosphorylation, and contraction. Relaxation of precontracted CA by 6AN and EPI was not blocked by calnoxin (10 μmol/l), a plasma membrane Ca(2+) ATPase inhibitor or by lowering extracellular Na(+), which inhibits the Na(+)/Ca(2+) exchanger (NCX), but cyclopiazonic acid (200 μmol/l), a sarcoplasmic reticulum Ca(2+) ATPase inhibitor, reduced (P < 0.05) 6AN- and EPI-induced relaxation. 6AN also attenuated phosphorylation of myosin phosphatase target subunit 1 (MYPT1) at Ser855, a site phosphorylated by Rho kinase, inhibition of which reduced (P < 0.05) KCl-induced CA contraction and 6AN-induced relaxation. By contrast, 6AN increased (P < 0.05) vasodilator-stimulated phosphoprotein (VASP) phosphorylation at Ser239, indicating that inhibition of G6PD increases PKA or PKG activity. Inhibition of PKG by RT-8-Br-PET-cGMPs (100 nmol/l) diminished 6AN-evoked VASP phosphorylation (P < 0.05), but RT-8-Br-PET-cGMPs increased 6AN-induced relaxation. These findings suggest G6PD inhibition relaxes CA by decreasing Ca(2+) influx, increasing Ca(2+) sequestration, and inhibiting Rho kinase but not by increasing Ca(2+) extrusion or activating PKG.     

Glucose-6-phosphate dehydrogenase and mouse Kupffer cell activation: an ultrastructural dual staining enzyme-cytochemical study

Glucose-6-phosphate dehydrogenase (G6PD) plays an important role in Kupffer cell function, especially in phagocytosis activity. Although it was suggested that Kupffer G6PD may be upregulated in Kupffer phagocytosis/activation, direct morphological evidence has been lacking. Acid phosphatase (ACP), a representative lysosomal enzyme, can be used as a cytochemical marker for phagocyte activation. Using an ultrastructural enzyme-cytochemical dual staining method, I simultaneously localized G6PD and ACP activity in mouse Kupffer cells on a cell-by-cell basis, and examined whether or not cytochemically detectable G6PD activity increases in phagocytosing/activated mouse Kupffer cells. Glucose-6-phosphate dehydrogenase labelings were observed in the cytoplasm and on the cytosolic side of the endoplasmic reticulum, and ACP labelings were seen in the lysosomes. In phagocytosing Kupffer cells, in which ACP deposits were observed not only in the lysosomes but also on the phagosomal membranes and phagosomal contents, G6PD labelings were denser than dormant Kupffer cells. Enzyme-cytochemically detectable G6PD activity increases in phagocytosing/activated mouse Kupffer cells. Kupffer cell G6PD, activated in phagocytosing Kupffer cells, may play an important role not only in liver defense but also in liver disease pathogenesis/pathophysiology.     

胎脑提取液对衰老小鼠海马神经元酶活性影响的实验研究

目的 观察胎脑提取液对衰老小鼠海马神经元酸性磷酸酶（ACP）和琥珀酸脱氢酶（SDH）活性的影响,探讨胎脑提取液的抗衰老作用。方法 选用健康昆明种小白鼠30只,随机分为3组;采用D-半乳糖制备亚急性衰老模型;酶组织化学方法结合显微图像分析。观察各组小鼠海马神经元ACP和SDH的活性。结果 衰老模型组与正常对照组相比,小鼠海马神经元ACP活性明显升高,SDH活性明显降低;给药组与衰老模型组相比,小鼠海马神经元ACP活性明显降低。SDH活性明显升高。结论 胎脑提取液可以延缓海马神经元的衰老进程,具有一定的抗衰老作用。     

食料对南亚果实蝇解毒酶活力的影响

昆虫解毒酶是一类异质酶系, 对分解大量的内源或外源有毒物质、维持正常生理代谢起着重要作用。本文采用生物化学的方法测定了5种寄主果实对南亚果实蝇Bactrocera tau Walker 3个虫态体内总蛋白含量和5种解毒酶的活力。双因子方差分析显示, 南亚果实蝇种群取食黄瓜Cucumis sativus L.、南瓜Cucurbita moschala L.、丝瓜Luffa cylindrical L.、冬瓜Benincasa hispida (Thunb.) Coqn.和苦瓜Momordica charantia L.后, 体内蛋白含量和解毒酶活性均存在显著差异。以丝瓜为食料时, 南亚果实蝇体内蛋白含量较高; 而以黄瓜和冬瓜为食料时蛋白含量则相对较低。在以上5种寄主果实间, 南亚果实蝇的羧酸酯酶（CarE）活性在黄瓜和南瓜上较高, 细胞色素P450 O-脱甲基和谷胱甘肽S-转移酶（GST）活性在苦瓜上较高, 酸性磷酸酯酶（ACP）和碱性磷酸酯酶（ALP）活性却分别在黄瓜和南瓜上较低。在幼虫、蛹和成虫3个虫态间, 解毒酶活性亦存在显著差异, 成虫具有较高的CarE活性;幼虫具有较高的细胞色素P450 O-脱甲基, GST和ALP活性,但具有较低的ACP活性;除ACP外,蛹期解毒酶活性均较低。据以上结果可以推测,南亚果实蝇解毒酶活力受寄主果实种类以及该种群本身发育阶段的影响。     

Immunochemical characterization of human red cell acid phosphatase isozymes

An immunological study was performed on human red cell acid phosphatase (ACP1) isozymes encoded by different alleles, each of which is expressed as an electrophoretically fast (f) isozyme and a slow (s) isozyme. These isozymes reacted as two immunochemically different groups. Allele-specific reactions were not detected between either the f isozymes or the s isozymes. Quantitation of ACP1 isozymes in red cells by crossed immunoelectrophoresis revealed a phenotype-dependent variation in the concentration of isozyme protein. A simple gene dosage effect was indicated and the ordering of the ACP1 alleles (ACP1*A < ACP1*B < ACP1*C < ACP1*E) was identical to that found for enzyme activity levels. Also, an allele effect on the proportion between s and f isozymes (s/f) was observed; the ordering here was ACP1* B < ACP1*A < ACP1*, which is the same as that reported for the susceptibility to modulation with purines. These variations in isozyme protein levels appear to account for the phenotypic differences in the intensity of the isozyme bands, when activity-stained after electrophoresis, and in the red cell enzyme activity levels. Investigation of two carriers of a Null allele showed no evidence of an aberrant protein product, and half-normal concentrations of enzyme protein were observed in the red cells of these individuals.     

The spatial distribution of acid phosphatase activity in ectomycorrhizal tissues depends on soil fertility and morphotype, and relates to host plant phosphorus uptake

Acid phosphatase (ACP) enzymes are involved in the mobilization of soil phosphorus (P) and polyphosphate accumulated in the fungal tissues of ectomycorrhizal roots, thereby influencing the amounts of P that are stored in the fungus and transferred to the host plant. This study evaluated the effects of ectomycorrhizal morphotype and soil fertility on ACP activity in the extraradical mycelium (ACP(myc)), the mantle (ACP(mantle)) and the Hartig net region (ACP(Hartig)) of ectomycorrhizal Nothofagus obliqua seedlings. ACP activity was quantified in vivo using enzyme-labelled fluorescence-97 (ELF-97) substrate, confocal laser microscopy and digital image processing routines. There was a significant effect of ectomycorrhizal morphotype on ACP(myc), ACP(mantle) and ACP(Hartig), while soil fertility had a significant effect on ACP(myc) and ACP(Hartig). The relative contribution of the mantle and the Hartig net region to the ACP activity on the ectomycorrhizal root was significantly affected by ectomycorrhizal morphotype and soil fertility. A positive correlation between ACP(Hartig) and the shoot P concentration was found, providing evidence that ACP activity at the fungus:root interface is involved in P transfer from the fungus to the host. It is concluded that the spatial distribution of ACP in ectomycorrhizas varies as a function of soil fertility and colonizing fungus.     

气调胁迫对咖啡豆象三种解毒酶活性与动力学参数的影响(英文)

为了分析气调处理对实验昆虫解毒酶性质的影响, 探讨酶活性变化与气调抗性形成的潜在关系, 本研究用高浓度二氧化碳胁迫处理咖啡豆象Araecerus fasciculatus (De Geer), 研究其羧酸酯酶(carboxylesterase, CarE)、 酸性磷酸酯酶(acid phosphatase, ACP)和谷胱甘肽转移酶(glutathione S-transferases, GSTs)的生物化学与毒理学性质。结果表明： 高浓度二氧化碳气调胁迫处理咖啡豆象3 h, 6 h和9 h, 其CarE酶活力分别升高 35.41%, 55.02%和88.98%。 CarE酶促动力学参数V_max分别升高26.13%, 31.77%和57.12%, K_m没有显著改变; 相应处理下, ACP活力分别升高34.53%, 72.45%和126.37%; GSTs 活力分别升高5.40%, 8.40%和17.59%。可见, 二氧化碳气调胁迫下, 实验昆虫可以通过调节部分解毒酶的酶活力或酶促动力学参数来应对不利环境; 酶与底物间的亲和力增强可能是昆虫在气调胁迫下保护机体免受伤害的一种代谢反馈信息。本研究可为昆虫气调杀虫及其抗（耐）气性形成机制提供一些基础信息。     

Protein, leucine aminopeptidase, esterase, acid phosphatase and photosynthetic responses of oleander (Nerium oleander L.) during cold acclimation and freezing treatments

Six-month-old oleander (Nerium oleander L.) pot plants, derived from vegetative propagation by cuttings, were tested for their ability to cold hardening. Damage of the non-acclimated (NA) plants was visible when treated by low freezing temperatures (below -2 degrees C). The responses of total proteins, leucine aminopeptidase (LAP), esterase (EST) and acid phosphatase (ACP) isoforms of NA and cold-acclimated (CA; 4 degrees C for 14 days) plants were compared using polyacrylamide gel electrophoresis. These molecular markers were also compared in NA and CA plants which received for 2h temperatures of 0, -2, -4, -6 and -8 degrees C. A new 38-kDa polypeptide appeared from day 7 to 14 during the acclimation treatment in the bark extracts and on day 14 in the leaf extracts. The above-mentioned polypeptide band (38 kDa) strongly appeared in all freezing treatments (0, -2, -4, -6 and -8 degrees C) in both bark and leaf extracts of the CA plants. Alterations in the number and the intensity of LAP and EST isoforms as well as in the intensity of ACP isoforms were observed in both bark and leaf of the CA oleander plants. A newly expressed EST isoform is proposed as biochemical marker for the cold acclimation treatment. CO2 assimilation rates (A) as well as transpiration rates (E) in NA plants were positive in 0 degrees C and negative in all temperatures below zero in the freezing treatments. In contrast, CO2 assimilation rates (A) and transpiration rates (E) were positive in CA plants in all temperatures of freezing treatment. A significant decrease (P<0.05) in chlorophyll (Chl) a, Chl a+b concentration and Chl a/b ratio were noticed in oleander plants during the acclimation treatment (from day 0 to 14), while Chl b concentration was unchanged at the respective time. On the other hand, no significant (P<0.05) differences were observed in the freezing treatments.     

Enzyme polymorphism and clinical variability of diseases: a study of diabetes mellitus

We investigated possible relations among four common neonatal manifestations of diabetic pregnancy (macrosomia, hypoglycemia, hypocalcemia, jaundice) and four enzyme polymorphisms (PGM1, ADA, AK1, ACP1 in a sample of infants born of diabetic mothers. The pattern of associations observed between the two sets of variables is consistent with known differences in enzymatic activity within phenotypes of each system, suggesting that low enzymatic activity may have unfavorable effects on fetal development and on adaptability of the neonate to the extrauterine environment, Some of the polymorphic enzymes studied influence fetal growth in normal pregnancy as well. Analysis of relations between genetic polymorphisms and the clinical pattern of common diseases may provide a better understanding of the genetic basis of the clinical variability of diseases within and between human populations.     

Isoforms of acyl carrier protein involved in seed-specific fatty acid synthesis

Seeds of coriandrum sativum (coriander) and Thunbergia alata (black-eyed Susan vine) produce unusual monoenoic fatty acids which constitute over 80% of the total fatty acids of the seed oil. The initial step in the formation of these fatty acids is the desaturation of palmitoyl-ACP (acyl carrier protein) at the delta(4) or delta(6) positions to produce delta(4)-hexadecenoic acid (16:1(delta(4)) or delta(6)-hexadecenoic acid (16:1(delta(6)), respectively. The involvement of specific forms of ACP in the production of these novel monoenoic fatty acids was studied. ACPs were partially purified from endosperm of coriander and T. alata and used to generate 3H- and 14C-labelled palmitoyl-ACP substrates. In competition assays with labelled palmitoyl-ACP prepared from spinach (Spinacia oleracea), delta(4)-acyl-ACP desaturase activity was two- to threefold higher with coriander ACP than with spinach ACP. Similarly, the T. alata delta(6) desaturase favoured T. alata ACP over spinach ACP. A cDNA clone, Cs-ACP-1, encoding ACP was isolated from a coriander endosperm cDNA library. Cs-ACP-1 mRNA was predominantly expressed in endosperm rather than leaves. The Cs-ACP-1 mature protein was expressed in E. coli and comigrated on SDS-PAGE with the most abundant ACP expressed in endosperm tissues. In in vitro delta(4)-palmitoyl-ACP desaturase assays, the Cs-ACP-1 expressed from E. coli was four- and 10-fold more active than spinach ACP or E. coli ACP, respectively, in the synthesis of delta(4)-hexadecenoic acid from palmitoyl-ACP. In contrast, delta(9)-stearoyl-ACP desaturase activity from coriander endosperm did not discriminate strongly between different ACP species. These results indicate that individual ACP isoforms are specifically involved in the biosynthesis of unusual seed fatty acids and further suggest that expression of multiple ACP isoforms may participate in determining the products of fatty acid biosynthesis.     

Investigations of the esterase, phosphatase, and sulfatase activities of the cytosolic mammalian carbonic anhydrase isoforms I, II, and XIII with 4-nitrophenyl esters as substrates

The esterase, phosphatase, and sulfatase activities of carbonic anhydrase (CA, EC 4.2.1.1) isozymes, CA I, II, and XIII with 4-nitrophenyl esters as substrates was investigated. These enzymes show esterase activity with 4-nitrophenyl acetate as substrate, with second order rate constants in the range of 753-7706M(-1)s(-1), being less effective as phosphatases (k(cat)/K(M) in the range of 14.89-1374.40M(-1)s(-1)) and totally ineffective sulfatases. The esterase/phosphatase activities were inhibited by sulfonamide CA inhibitors, proving that the zinc-hydroxide mechanism responsible for the CO(2) hydrase activities of CAs is also responsible for their esterase/phosphatase activity. CA XIII was the most effective esterase and phosphatase. CA XIII might catalyze other physiological reactions than CO(2) hydration, based on its relevant phosphatase activity.     

ACP1 and human adaptability 2. Association with season of conception

We have studied the pattern of association between the season of conception and cytosolic low molecular weight phosphotyrosine phosphatase (ACP1) genetic polymorphism in 329 consecutively newborn infants from the population of Penne and 361 consecutively newborn infants from the population of Rome. In addition, 329 mothers were studied in the population of Penne. A concordant, highly significant association was observed in the two populations between ACP1 parameters and the season of conception of newborn infants. The total activity of ACP1 shows a minimum in infants conceived in January–February and a maximum in those conceived at the end of the solar year. Analysis of the joint mother-newborn ACP1 distribution in relation to the season of fertilisation has shown that among mothers carrying ACP1*A (the allele showing the lowest activity), the proportion of newborns carrying this allele is higher in those conceived in the first months of the year than in those conceived subsequently. Since ACP1 probably functions as a phosphotyrosine phosphatase and as a flavin mononucleotide phosphatase, low activity could enhance the metabolic rate and would be advantageous in a cold environment. The cycle of variation of ACP1 in infants follows the cycle of solar illumination. It is possible that individuals who have a genetic background allowing them to adapt easily and readily to seasonal demand are more successful in reproducing themselves. The population of zygotes conceived in a given season would therefore reproduce the pattern of gene combination more fit for that season. Received: 15 June 1997 / Accepted: 31 July 1997