• Journal of Microbiology
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• v.37 no.1
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• pp.21-26
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• 1999

Two novel calcium-binding proteins, named CAB-I and CAB-II, have been isolated from Streptomyces coelicolor. Purification of the calcium-binding proteins involved heat treatment, fractionation with ammonium sulfate, acid treatment, anion exchange and hydrophobic interaction column chromatography, FPLC gel filtration, and preparative isoelectric focusing. A chelex competitive assay and 45Ca autoradiography verified the calcium-binding ability of the proteins. The major band CAB-II has an apparent molecular weight of 26,000 determined by SDS-polyacrylamide gel electrophoresis and 340,000 determined by gel filtration. The isoelectric point of this molecule showed the acidic nature of the molecule. N-terminal amino acid sequence analysis shows homology to rat Ca2+/calmodulin-dependent protein kinase-II (CAB-II) and yeast phosphoprotein phosphatase (CAB-I).

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1179-1188
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• 2018

This study aimed to investigate the combined effect of using natural calcium mixtures and various binding ingredients as replacers for synthetic phosphate in ground pork products. We performed seven treatments: control (0.3% phosphate blend), treatment 1 (0.5% natural calcium mixtures [NCM, which comprised 0.2% oyster shell calcium and 0.3% egg shell calcium powder] and 0.25% egg white powder), treatment 2 (0.5% NCM and 0.25% whey protein concentrate), treatment 3 (0.5% NCM and 0.25% concentrated soybean protein), treatment 4 (0.5% NCM and 0.25% isolated soybean protein), treatment 5 (0.5% NCM and 0.25% carrageenan), and treatment 6 (0.5% NCM and 0.25% collagen powder). All the treatment mixtures had higher pH and lower cooking loss than the control, which was treated with phosphate. We found that NCM and binding ingredients had no negative effects on the moisture content, lightness, and yellowness of the cooked ground pork products. Treatments 3 and 4 showed significantly lower CIE $a^*$ values than the control. Treatments 2 and 6 improved the textural properties of the products. In conclusion, the combination of NCM with whey protein concentrate or collagen powder could be suitable for producing phosphate-free meat products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.3
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• pp.212-218
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• 1983

The effect of dietary calcium and magnesium on the 3-Hydroxy-3-methyl-glutaryl coenzyme A reductase (E.C. 1.1.1.34) in rabbit's liver microsomal protein was studied for a period of 4 weeks using isocalories and isonitro-genous as a basal diet. The experimental rabbits fed the following basal diets, such as crude protein 68.45%, carbohydrates 13.38%, fats 16.17% and added some sorts of calcium and magnesium, according to experimental plan making. The subject rabbits were divided into 9 feeding groups. The results are summarized as follows. Body weight gains per week of the groups fed magnesium and basal diet showed a little bit increase, but the groups fed calcium and basal diet showed a little bit decrease compare with control group. In case of serum magnesium, control group was 9.5mg% groups fed basal diet and magnesium were 8.27mg% in average, groups fed basal diet and calcium were 4.45mg% in average. In case of serum calcium, control group was 15.3mg%, groups fed basal diet and magnesium were 14.6mg% in average, groups fed basal diet and calcium were 14.1mg% in average. There was no great difference between magnesium fed groups in serum calcium. In serum triglyceride, control group was 82.8mg%, groups fed magnesium and basal diet were 60.3mg% in average, groups fed calcium and basal diet were 69.5mg% in average. The calcium fed groups were higher than the magnesium fed groups in serum triglyceride. In serum cholesterol, control group was 80mg%, groups fed magnesium and basal diet were 64.3mg% in average, groups fed calcium and basal diet were 56.3mg% in average. The calcium fed groups were lower than the magnesium fed groups in serum cholesterol. In case of the 3-Hydroxy-3-methylglutaryl coenzyme A reductase activity, control group was 0.998nmol/min/mg protein, groups fed magnesium and basal diet of HMG-CoA were 0.849nmol/min/mg in average.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.59-69
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• 1996

Effects of dietary calcium(Ca), protein, and phosphorus(P) intake on bone mineral density (BMD) were investigated in 129 Korean premenopausal women(age 31-54 years) without diagnosed disease. BMD was measured at the spine(vertebrae L2-4) and femur(neck, Ward's triangle and trochanter). By stepwise multiple regression analysis it was shown that protein, Ca, and P intakes affected most significantly on BMD at the vertebrae L2-4, protein and P intakes affected most significantly on BMD at the femoral neck and Ward's triangle, and body mass index(BMI) affected most significantly on BMD at the trochanteric region. When ate-matched BMD % at the vertebrae L2-4 and all femoral sites was grouped by three levels(<90%, 90-99%, >=100%), only at the vertebrae L2-4>=100% and 90-99% groups had higher Ca intakes than <90% groups. When Ca, protein and P intakes of the recommended level for Korean(RDA) were grouped by three levels (Ca or P ; <=650mg/d, 650-750mg/d, >=750mg/d, Protein ; <=55g/d, 55-60g/d, >=65g/d), only at the vertebrae L2-4>55g/d of protein intake had higher age-matched BMD % than <=55g/d intake, >=750mg/d of Ca and P intakes, age-matched BMD % than <=650mg/d. In RDA range of Ca, protein, and P intakes, age-matched BMD % of the vertebrae L2-4 and all femoral sites was greater than 90%. Correlation between Ca intake and vertebral BMD was examined closer. There was more significant linear correlation between vertebral BMD and Ca intake below 800mg/d(r=0.346, p<0.0001)than above(r=0.376, p<0.019), implying a threshold effect and vertebral BMD was better expressed as a function of the logarithm of calcium intake(r=0.3881, p<0.0001). These results suggest that Ca, protein, and P intakes greater than RDA help to maintain proper BMD in middle-aged prementopausal women. Especially dietary Ca have important role in increasing the vertebral BMD and 800mg/d of Ca intake is optimum amount.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.204-209
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• 2003

Utilization of soluble protein recovered from surimi wastewater using calcium powder of cuttle bone were examined. The crude ash content of the heat-induced surimi gel was increased linearly by increasing substitution ratio of recovered protein-ATC toward commercial surimi. Moisture (approximately $76\%$) and lipid $(0.2\%)$ contents were not change, but their protein contents were decreased 15.7 to $14.3\%$ depend on increasing of substitution ratio. The white index of the heat-induced surimi gel by color meter was increased up to $10\%$ of substitution ratio. There were no difference between $0\%\;and\;5\%$ substituted surimi gel in the gel strength. The sensory score on white index and texture of the heat-induced surimi gel did not change in 0 to $10\%$ as a substitution ratio of recovered protein-ATC toward commercial surimi, while decreased in more $15\%.$ The optimal substitution ratio of recovered protein-ATC as a bulking agent was $10\%.$ The heat-induced surimi gel prepared with $10\%$ substitution of recovered protein-ATC was similar to the content and composition of total amino. acids, and superior to calcium content and the ratio of calcium and phosphorus toward those of commercial surimi.

• The Korean Journal of Physiology
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• v.27 no.2
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• pp.151-162
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• 1993

In order to investigate the effect of intracellular cyclic GMP on calcium current the whole-cell patch clamp technique with internal perfusion method was used in isolated ventricular myocytes of the rabbit. Cyclic GMP, 8-bromo-cyclic GMP, cyclic AMP, isoprenaline and forskolin were perfused into cells and their effects on calcium current were analysed by applying depolarizing step pulses of + 10 mV in amplitude far 300 msec from holding potential of - 40 mV. Not only cyclic AMP $(100\;{\mu}M)$ but also cyclic GMF $(100\;{\mu}M)$ increased the basal calcium current. 8-Bromo-cyclic GMP $(100\;{\mu}M)$, a good stimulator of the cyclic GMP-dependent protein kinase, also increased the basal calcium current and its peak amplitude of calcium current was larger than that in the presence of cyclic AMP or cyclic GMP alone. In the presence of $100\;{\mu}M$ cyclic GMP or $100\;{\mu}M$ 8-bromo-cyclic GMP, already augmented calcium current was potentiated by intracellular application of $100\;{\mu}M$ cyclic AMP or $1\;{\mu}M$ isoprenaline or $1\;{\mu}M$ forskolin. In the presence of cyclic GMP, acetylcholine reduced the calcium current only when the calcium current was increased by isoprenaline. From the above results it could be concluded that intracellular perfusion with cyclic GMP increases the basal calcium current via a mechanism involving a cyclic GMP-dependent protein kinase.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.633-636
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• 2000

Translationally controlled tumor protein (TCTP), also known as IgE-dependent histamine-releasing factor, is a growth-related tumor protein. Although the primary sequence of rat TCTP does not reveal any recognizable $Ca^{2+}$ -binding motif, previous studies have demonstrated that rat TCTP consisting of 172 amino acids is a $Ca^{2+}$ -binding protein. However. the region of TCTP required for $Ca^{2+}$ interaction has not been mapped to the molecule. Here, we reported that the $Ca^{2+}$ binding region of TCTP which was mapped by using a combination of deletion constructs of rat TCTP and $^{45}Ca^{2+}$-overlay assay. was confined to amino acid residues 81-112. This binding domain did not show any peculiar loop of calcium- binding motif such as CaLB domain and EF hand motif and it seems to be constituted of random coil regions neighboring the a helix. Thus, our data confirm that TCTP is a novel family of $Ca^{2+}$ -binding protein.

• BMB Reports
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• v.31 no.5
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• pp.468-474
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• 1998

Membrane depolarization in PC12 cells induces calcium influx via an L-type voltage-sensitive calcium channel (L-VSCC) and increases intracellular free calcium, which leads to tyrosine phosphorylation of epidermal growth factor (EGF) receptor and the associated adaptor protein, She. This activated EGF receptor complex then can activate mitogen-activated protein (MAP) kinase, as in nerve growth factor (NGF) receptor activation. In the present study, we investigated the role of EGF receptor in the signaling pathway initiated by membrane depolarization of PC12 cells. Prolonged membrane depolarization induced phosphorylation of extracellular signal-regulated kinase (ERK) within 1 min in undifferentiated PC12 cells. Pretreatment of PC12 cells with the calcium chelator EGTA abolished depolarization-stimulated ERK phosphorylation, but NGF-induced phosphorylation of ERK was not affected. The chronic treatment of phorbol ester, which down-regulated the activity of protein kinase C (PKC), did not affect the phosphorylation of ERK upon depolarization. In the presence of an inhibitor of EGF receptor, neither depolarization nor calcium ionophore increased the level of ERK phosphorylation. These data imply that the EGF receptor is functionally necessary to activate ERK and neurite outgrowth in response to the prolonged depolarization in PC12 cells, and also that PKC is apparently not involved in this signaling pathway.

• The Korean Journal of Food And Nutrition
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• v.7 no.3
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• pp.177-182
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• 1994

The effect of phosphate salt (NafHP04) and sodium citrate on the emulsion stability of soy protein isolate (SPI) in the presence of calcium was investigated in terms of salt concentration and addition order. Both phosphate and citrate salts decreased the solubility of SPI despite their pH enhancing effects. Addition of calcium chloride (CaCl2) significantly decreased ES, which showed nearly negligible at more than 3 mM CaCl2 concentration. When Na2HP04 were added in the presence of 5 mM Cac12, 55 greatly increased up to 20mM concentration, above which however ES decreased. It was found that the addition order of Na2HPO4 and CaCl2 affected ES. The addition of phosphate and subsequent CaCl2 exhibited the higher 55 than the reverse order. In both cases, the overall ES profile was found to be nearly similar to the solubility profile of SPI, indicating the positive relationship between solubility and emulsion stability of SPI in the presence of calcium. Similar trend to the phosphate effect on ES was also observed for sodium citrate in the presence of calcium.

• Molecules and Cells
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• v.24 no.2
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• pp.276-282
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• 2007

Protein phosphorylation is one of the major mechanisms by which eukaryotic cells transduce extracellular signals into intracellular responses. Calcium/calmodulin ($Ca^{2+}/CaM$)-dependent protein phosphorylation has been implicated in various cellular processes, yet little is known about $Ca^{2+}/CaM$-dependent protein kinases (CaMKs) in plants. From an Arabidopsis expression library screen using a horseradish peroxidase-conjugated soybean calmodulin isoform (SCaM-1) as a probe, we isolated a full-length cDNA clone that encodes AtCK (Arabidopsis thaliana calcium/calmodulin-dependent protein kinase). The predicted structure of AtCK contains a serine/threonine protein kinase catalytic domain followed by a putative calmodulin-binding domain and a putative $Ca^{2+}$-binding domain. Recombinant AtCK was expressed in E. coli and bound to calmodulin in a $Ca^{2+}$-dependent manner. The ability of CaM to bind to AtCK was confirmed by gel mobility shift and competition assays. AtCK exhibited its highest levels of autophosphorylation in the presence of 3 mM $Mn^{2+}$. The phosphorylation of myelin basic protein (MBP) by AtCK was enhanced when AtCK was under the control of calcium-bound CaM, as previously observed for other $Ca^{2+}/CaM$-dependent protein kinases. In contrast to maize and tobacco CCaMKs (calcium and $Ca^{2+}/CaM$-dependent protein kinase), increasing the concentration of calmodulin to more than $3{\mu}M$ suppressed the phosphorylation activity of AtCK. Taken together our results indicate that AtCK is a novel Arabidopsis $Ca^{2+}/CaM$-dependent protein kinase which is presumably involved in CaM-mediated signaling.