• Journal of Life Science
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• v.18 no.11
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• pp.1507-1512
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• 2008

In spite of long research period for Salmonella typhi, little information is known about the pathogenesis mechanism of human typhoid fever caused by S. typhi due to lack of infection model in animals. A wild-type of S. typhi Ty2 strain requires cysteine to grow on minimal media. We hypothesized that this cysteine requirement may restrict colonization of S. typhi in animals during infection process. Among the S. typhi strains carrying Salmonella typhimurium genomic library, we have isolated three S. typhi transformants growing on minimal media without cysteine. Although there were three ORFs in DNA of pBP71, the STM1490 ORF complemented cysteine auxotrophy of S. typhi. Analysis of the deduced amino acid sequence of the STM1490 homolog in S. typhi revealed that there are differences in two amino acids. Plasmids containing amino acid substitutions in STM1490 supported S. typhi growth on minimal media without cysteine, indicating irrelevance of these two amino acids to STM1490 function. These results tells us that there are other factors or systems involved in cysteine requirement of S. typhi.

• Parasites, Hosts and Diseases
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• v.36 no.2
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• pp.133-142
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• 1998

A 40 kDa cysteine protease was purified from the crude extract of adult worms of GMnnophalloines seoi by two consecutive steps: Sephacryl S-200 HR and DEAE- Sephacel chromatography. Enzyme activities were completely inhibited by cysteine protease inhibitors, L-lorans-epoxysuccinylleucylamido (4-guanidino) butane (E-64) and iodoacetic acid, strongly suggesting that the purified enzyme belongs to the cysteine family of proteases. The enzyme was maximally acive at pH 4.5 in 0.1 M of buffer, and its activity was greatly potentiated in the presence of 5 mM dithiothreitol. The protease degraded macromolecules with differential capabilities : it degraded extracellular matrix proteins, such as collagen and fibronectin, with a stronger activity against collagen than fibronectin . However, the enzyme digested hemoglobin and human immunoglobulins only slightly. leaving them nearly intact after an overnight reaction. Our results suggest that the cysteine protease of G. seoi adults is potentially significant in the nutrient uptake from the host intestine.

• Analytical Science and Technology
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• v.13 no.6
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• pp.736-742
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• 2000

The purpose of this study was to determine the homocysteine (Hey), methionine (Met) and cysteine (Cys) using solid phase micro-extraction (SPME)/gas chromatography (GC)-mass spectrometry (MS) in human plasma and to correlate between the plasma concentration of homocysteine with coronary artery disease. The homocysteine, methionine and cysteine in blood can be used as biomarkers for the risk assessment of vascular disease. The plasma homocysteine level for the coronary artery disease patients was higher than general patients. The concentration ranges of the Hcy, Met and Cys for coronary artery disease patients were $18.47-33.38{\mu}mol/L$, $30.16-55.72{\mu}mol/L$ and $183.16-387.32{\mu}mol/L$, respectively. This method showed good sensitivity and convenience.

• Journal of the Korean Chemical Society
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• v.50 no.5
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• pp.362-368
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• 2006

SH group modifying chemicals were used to characterize the eight cysteine residues of cabbage PLD. 5,5-dithiobis(2-nitrobenzoate)(DTNB) was used to titrate the SH group of cysteine residues . Based on the optical density at 412nm due to the reduced DTNB, 4 SH groups are found to be present in a native PLD while 8 SH groups in the denatured PLD whose tertiary structure was perturbed by 8M urea. The results imply that among the 8 cysteine residues of PLD, the half(4) are exposed on the surface whereas the other half are present at the interior of the enzyme tertiary structure. The PLD was inactivated by SH modifying reagents such as p-chloromercuribenzoate(PCMB), iodoacetate, iodoacetamide, and N-ethylmaleimide. At the addition of dithiothreitol(DTT) only the PCMB inhibited PLD activity was recovered reversibly. The micro-environment of the exposed SH group of cysteine residues was examined with various disulfide compounds with different functional groups and we found that anionic or neutral disulfides appear to be more effective than the positively charged cystamine for inactivating the PLD activity. The effect of redox state of cysteine residues on the PLD activity was further explored with H2O2. The oxidation of SH groups by H2O2 inhibited the PLD activity more than 70%, which was mostly recovered by DTT. From these results, we could confirm chemically that all the cysteine residues of PLD are present as in their reduced SH forms and the 4 SH groups exposed on the surface of the enzyme may play important roles in the regulation of PLD activity.

• Parasites, Hosts and Diseases
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• v.36 no.4
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• pp.261-268
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• 1998

The present study was undertaken to investigate the role of cysteine proteinase of Trichomonas vaginalis in escaping from host defense mechanism. A cysteine proteinase of T. vaginalis was purified by affinity chromatography and gel filtration. Optimum pH for the purified proteinase activity was 6.0. The proteinase was inhibited by cysteine and serine proteinase inhibitors such as E-64, NEM, IAA, leupeptin. TPCK and TLCK, and also by $Hg^{2+}$, but not affected by serine-, metallo-, and aspartic proteinase inhibitors such as PMSF, EDTA and pepstatin A. However, it was activated by the cysteine proteinase activator, DTT. The molecular weight of a purified proteinase was 62 kDa on gel filtration and 60 kDa on SDS-PAGE. Interestingly, the purified proteinase was able to degrade serum IgA, secretory IgA, and serum IgG in time- and dose-dependent manners. In addition, the enzyme also degraded hemoglobin in a dose-dependent manner. These results suggest that the acidic cysteine proteinase of T. vaginalis may play a dual role for parasite survival in conferring escape from host humoral defense by degradation of immunoglobulins, and in supplying nutrients to parasites by degradation of hemoglobin.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.1
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• pp.40-45
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• 2014

Objectives : Mild cognitive impairment(MCI) and dementia of Alzheimer's type(AD) are characterized by progressive decline of cognitive abilities and a wide range of neuropsychiatric symptoms like depression. Among various diagnostic tools of AD, many studies showed that elevated levels of serum total homocysteine are associated with increased risk of developing Alzheimer's disease, depression and other neuropsychiatric disorders. We investigated whether elevated homocysteine concentrations are associated with depressive symptoms in MCI and AD. Methods : A total of 86 patients diagnosed with MCI or AD participated. Total serum homocysteine levels in fasting blood samples were measured. We examined cognitive symptoms by MMSE-KC, Global Deterioration Scale(GDS), Clinical dementia rating(CDR) and depressive symptoms by Korean version of Geriatric Depression Scale(K-GDS). Results : The total serum homocysteine levels were significantly higher in MCI with depression than in MCI without depression. There was no significant difference in the mean homocysteine levels between AD patients with depression and AD patients without depression. The total homocysteine levels showed a negative correlation with MMSE-KC and a positive correlation with CDR, GDS. Conclusions : These findings suggest that elevated homocysteine level is a risk factor for the decline of cognitive function and depression. We found a significant relationship between elevated serum homocysteine level and depressive symptoms in MCI. But our study had several limitations, thus more research is needed to confirm this finding.

• Journal of Life Science
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• v.19 no.5
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• pp.573-580
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• 2009

It has been previously reported that the carboxyl terminal residues 276 and 277 of ${\alpha}$-tropomyosin are important for actin affinity. In order to investigate actin affinities of these two residues of skeletal (HA) and smooth (QT) muscle ${\alpha}$-tropomyosins, a series of mutant tropomyosins were constructed in which residues at either 276 or 277 were individually replaced with a cysteine residue for chemical modification. These mutants were overexpressed in E. coli as unacetylated and Ala-Ser (AS) dipeptide fusion forms. While actin affinities of unacetylated tropomyosins were considerably low, those of AS/TMs were remarkably higher than those of corresponding unacetylated tropomyosins. However, actin affinities of AS/TM24 (QC) and AS/TM29 (HC) were dramatically lower than those of other AS/TMs and were close to those of unacetylated tropomyosins. In addition, actin affinities of unacetylated TM24 (QC) and TM29 (HC) failed to be restored in the presence of troponin, unlike unacetylated TM10 (HA) and TM23 (CA). These results indicated that the presence of a cysteine residue at 277 caused a drastic decrease in actin affinity, and also that the residue 277 is important for actin affinity of ${\alpha}$-tropomyosin. Since TM23 (CA) showed high actin affinity, it may serve as a valuable tool for chemical modification studies for investigating the interaction of the carboxyl terminal residues of ${\alpha}$-tropomyosin with actin and/or troponin.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.673-680
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• 2019

This study was conducted to investigate the effects of plasma homocysteine concentration on the brachial-ankle pulse wave velocity between the normal homocysteine group and the asymptomatic high homocysteine group. 435 subjects who visited the general health examination center from April 1 to October 31, 2016, as well as to compare the direct correlation of the brachial-ankle pulse wave velocity, which indirectly reflects the homocysteine test and arterial stiffness, as a predictor of future cardiovascular outcome. As a result of the study, age, waist circumference, BUN, and plasma creatinine were significantly higher, and HDL was significantly lower in the high homocysteine group (> $15{\mu}mol/L$) than in the normal homocysteine group (< $15{\mu}mol/L$) (p=0.05). In addition, homocysteinemia was associated with smoking and drinking (p<0.001) and was significantly higher in males (p<0.001). The right and left brachial-to-ankle pulse wave velocities were significantly higher in the high homocysteine group (right p<0.001, left p=0.003) before calibrating the relevant variables. There was no significant difference between right and left brachial-to-ankle pulse wave velocities after calibrating the relevant variables. Therefore, further studies on the independent association of lowering homocysteine concentration and prevention of cardiovascular disease and the relationship between homocysteine and renal function are needed.

• 한국유가공학회:학술대회논문집
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• 2005.06a
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• pp.13-35
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• 2005

The trend towards ageing populations has been observed over many years in Europe and the US but has accelerated significantly in developed countries in Asia including Japan and South Korea. In the latter country the elderly population (65+) has increased 5-fold between 1960 and 2000 and this group will comprise 40% of the population by 2050. This creates a new socio-economic group with specific demands and considerable spending power. As ageing occurs a range of changes occur in the body that can be moderated by adjustments in nutrition. A significant body of evidence points to changes in the balance of glutathione synthesis and utilisation as people age. Glutathione is the most important natural anti-oxidant of the body and the amounts present can become limited by available cysteine in the diet. A cysteine-enriched peptide product, Cysteine Peption$^{TM}$ has been developed by DMV International for dietary supplement and food applications. A qualitative consumer trial has indicated benefits including improved sleep and more energy. Animal and clinical trials will be described that provide indications on bioavailability and possible mechanisms of action of Cysteine Peption$^{TM}$ with particular focus on the ageing population.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.800-807
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• 1989

No-time dough process utilizing ascorbic acid as an oxidant was investigated. The farinograph absorption was increased as the amount of L-cysteine increased, while stability and peak time decreased up to 40 and 30 ppm of L-cysteine, respectively. Extensibility of the dough was increased with the increment of L-cysteine, but the ratio of resistance to extensibility was significantly decreased. At the same level of L-cysteine, the addition of ascrobic acid by 1.5 times decreased the farinograph absorption. However, the stability and peak time remained relatively unchanged upon addition of ascrobic acid. Extensibility and resistance of dough were respectively decreased and increased in the presence of both L-cysteine and ascorbic acid. In the range of 30-50 ppm of cysteine, the mixing time decreased and the baking absorption was increased by 1% as the cysteine was increased by 10 ppm. The ascorbic acid had no effects on absorption and mixing time. Bread produced by no·time dough process had no break and shred. The optimum concentrations of L-cysteine and ascorbic acid for no-time dough process were 40 and 100ppm, respectively.