Ghrelin, a hormone mainly produced and released by the stomach, has numerous functions, including releasing growth hormones, regulating appetite, and processing sugar and lipids. Researchers have made great efforts to study the relationship between ghrelin and metabolic diseases. It is believed that human butyrylcholinesterase (hBChE) could hydrolyze ghrelin to the inactive form (desacyl-ghrelin). However, the low catalytic activity of wild hBChE against ghrelin hinders the clinical application. Recently, a soluble catalytically active hBChE mutant was successfully expressed in Escherichia coli for the first time. We then adopted HotSpot Wizard 3.0 to analyze the mutant structure and rationally selected 10 mutants. Furthermore, we determined the catalytic activities of the mutants against several substrates and the thermostability of these mutants. The results showed that the mutants E197D and A199S improved catalytic activity against ghrelin by 4.6 times and 3.5 times, respectively. The findings provide clues for treating endocrine diseases with the agents for regulating ghrelin.
Ghrelin/genetics* ; Butyrylcholinesterase/genetics* ; Humans ; Escherichia coli/metabolism* ; Mutation ; Catalysis ; Recombinant Proteins/metabolism*

Several studies have shown the mechanisms and importance of immune responses against Toxoplasma gondii infection and the notable role of cholinesterases in inflammatory reactions. However, the association between those factors has not yet been investigated. Therefore, the aim of this study was to evaluate the acetylcholinesterase (AChE) activity in blood and lymphocytes and the activity of butyrylcholinesterase (BChE) in serum of rats experimentally infected with T. gondii during the acute phase of infection. For that, an in vivo study was performed with evaluations of AChE and BChE activities on days 5 and 10 post-infection (PI). The activity of AChE in blood was increased on day 5 PI, while in lymphocytes its activity was enhanced on days 5 and 10 PI (P<0.05). No significant difference was observed between groups regarding to the activity of BChE in serum. A positive (P<0.01) correlation was observed between AChE activity and number of lymphocytes. The role of AChE as an inflammatory marker is well known in different pathologies; thus, our results lead to the hypothesis that AChE has an important role in modulation of early immune responses against T. gondii infection.
Acetylcholinesterase/blood/*metabolism ; Animals ; Butyrylcholinesterase/blood/*metabolism ; Humans ; Lymphocytes/enzymology/parasitology ; Male ; Rats ; Rats, Wistar ; Toxoplasma/*physiology ; Toxoplasmosis/*enzymology/genetics/parasitology

OBJECTIVETo study the activity of esterases, including butyrylcholinesterase (BchE), carboxylesterase (CarbE), paraoxonase (PonE) and acetylcholinesterase (AChE), and to explore the effect of genetic polymorphism on the activity of esterase for workers exposed to organophosphorus pesticides (OPs).

METHODSTwo hundred and forty-one long term OPs directly exposed workers and 151 indirectly exposed workers in the same factory were taken as study group. One hundred and sixty unexposed persons were taken as control group. The activity of serum enzymes was measured and the polymorphic distribution was detected using 7900 genotype detecting system and CMOS Chip technique. The effect of long-term exposure to organophosphorus pesticides was analyzed.

RESULTSThe activities of BchE, CarbE and PonE were independent on the gender or age in control group. Average values of Carb and BchE activities of directly and indirectly exposed workers were lower than those in control group respectively. PonE activity in directly exposed group was lower than that in control group. AChE activity in directly exposed group was lower than that in indirectly exposed group. All the differences were significant (P < 0.01). In the direct exposure group, the frequency of three variants of butyrylcholinesterase gene K (BCHE-K) polymorphism was 74.3%, 24.1% and 1.6% for UU, UK and KK respectively. Frequency of allele U and K was 0.863 and 0.137 respectively in the same group. Frequency of three variants of PON192 polymorphism was 15.0%, 45.5% and 39.5% for AA, AB and BB respectively in direct exposure group. Gene frequency of low activity (PON*A) and high activity (PON*B) was 0.378 and 0.622 respectively. Frequency of three variants of PON55 polymorphism was 96.2%, 3.8% and 0% for MM, LM and LL respectively in direct exposure group. Frequency of allele M and L was 0.981 and 0.019 respectively in the same group. The activity of PON was different in various genotypes of PON192 and PON55.

CONCLUSIONThe long-term exposure to OPs could inhibit the activities of CarbE, BchE, PonE and ACh E in different level. The genetic polymorphisms of PON192 and PON55 affect the activity of PonE, which is related to the detoxification of OPs and health impact.

Acetylcholinesterase ; metabolism ; Adult ; Alleles ; Aryldialkylphosphatase ; genetics ; metabolism ; Butyrylcholinesterase ; genetics ; metabolism ; Carboxylesterase ; metabolism ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Middle Aged ; Occupational Exposure ; Organophosphorus Compounds ; adverse effects ; Pesticides ; adverse effects ; Polymorphism, Single Nucleotide

OBJECTIVETo study the relationship between the polymorphism of butyrylcholinesterase (BChE, EC 3.1.1.8) and paraoxonase (PonE, EC 3.1.8.1), and the individuals' genetic susceptibility to organophosphates pesticides (OPs) exposure.

METHODS75 OPs exposure workers were selected to determine their BChE-K, PON-192 and PON-55 genotypes using PCR-RFLP. The accumulative symptom scores and the whole blood acetylcholinesterase activity (mmol x h(-1) x ml(-1)) were used as health index. Firstly, the health condition related to single gene site of the three gene loci was analyzed to determine which kinds of genotype were susceptible. Then, used the multiple variance analysis was to see if there existed interactions among these three gene loci. Finally, established the multi-factor linear regression equation, in which considered some other factors that might influence the health situation such as age, gender and the exposure time. According to the equation, could get the accumulative symptom scores of each kind of subpopulation of different genotypes.

RESULTSThe mean AChE activities of the exposed workers with BChE-K genotype UU (61 cases), genotype UK (12 cases) and genotype KK (2 cases) were 105.0 +/- 23.0, 84.4 +/- 16.4, 79.0 +/- 9.9, respectively; The accumulative symptom scores were 3.7 +/- 3.8, 9.2 +/- 3.0, 12.5 +/- 0.7, respectively. The AChE activities of the exposed workers with PON-192 genotype BB (37 cases), genotype AB (27 cases) and genotype AA (11 cases) were 116.8 +/- 15.1, 91.2 +/- 15.6, 72.3 +/- 21.4, respectively; The accumulative symptom scores were 2.0 +/- 3.2, 6.7 +/- 3.3, 9.7 +/- 1.8, respectively. Similarly, the AChE activities of the exposed workers with PON-55 genotype LL (70 cases) and genotype LM (5 cases) were 102.4 +/- 23.0, 82.8 +/- 22.0; The accumulative symptom scores were 4.5 +/- 4.2, 9.2 +/- 3.6, respectively. Single variance analysis showed that the accumulative symptom scores of the individuals with abnormal homozygote of these three gene loci were the highest, which indicated that they were most susceptible to OPs. Multiple variance analysis showed there were no interactions among the three gene loci. Age, gender and exposure time had no statistical significance, while genotypes of the three gene loci had statistical significance to health situation.

CONCLUSIONGenotypes of BChE-K, PON-192 and PON-55 are related to susceptibility to OPs exposure.

Adult ; Aryldialkylphosphatase ; genetics ; Butyrylcholinesterase ; genetics ; Female ; Genetic Predisposition to Disease ; Genotype ; Humans ; Male ; Middle Aged ; Occupational Exposure ; Organophosphorus Compounds ; adverse effects ; Pesticides ; adverse effects ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length