• Fisheries and Aquatic Sciences
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• v.1 no.2
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• pp.209-215
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• 1998

Trypsin-like enzyme was purified from shrimp hepatopancreas through Q-Sepharose ionic exchange, benzamidine Sepharose-6B affinity, and Superdex 75 gel chromatography. Purity of trypsin-like enzyme was increased 69-fold with $44\%$ yield. The enzyme consisted of a single polypeptide chain with a molecular weight (M.W.) of 32 kDa judged by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was completely inactivated by serine enzyme inhibitors such as soybean trypsin inhibitor (SBTI), tosyl-L­lysine chloromethyl ketone (TLCK), and leupeptin. However, the enzyme was not affected by tosyl-L-phenylalanine chloromethyl ketone (TPCK) which is a chymotrypsin specific inhibitor. The enzyme had no activity against benzoyl-tyrosine ethyl ester (BTEE) which is a chymotrypsin specific substrate. The enzyme showed high activity on the carboxyl terminal of Phe, Tyr. Glu, Arg, and Asp. However. no activity was detected against the carboxyl terminal of Pro, Trp, Cys, Gly, Val, and Ala.

• 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.

• BMB Reports
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• v.47 no.4
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• pp.192-196
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• 2014

RNA polymerase II carboxyl-terminal domain (pol II CTD) phosphatases are a newly emerging family of phosphatases that are members of DXDX (T/V). The subfamily includes Small CTD phosphatases, like SCP1, SCP2, SCP3, TIMM50, HSPC129 and UBLCP. Extensive study of SCP1 has elicited the diversified roles of the small C terminal domain phosphatase. The SCP1 plays a vital role in various biological activities, like neuronal gene silencing and preferential Ser5 dephosphorylation, acts as a cardiac hypertrophy inducer with the help of its intronic miRNAs, and has shown a key role in cell cycle regulation. This short review offers an explanation of the mechanism of action of small CTD phosphatases, in different biological activities and metabolic processes.

• Macromolecular Research
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• v.12 no.1
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• pp.63-70
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• 2004

We have synthesized various types of poly(ethylene glycol) (PEG)-ibuprofen conjugates by the nucleophilic substitution of bromo-terminated PEG with ibuprofen-Cs salt; PN (Pluronic) was also used in place of PEG. All the bromo-terminated PEGs and PN were obtained in high yield. Conversions of the terminal hydroxyl groups to bromo-termini were quantitative, as were the drug conjugation processes. The Ι$_1$/Ι$_3$values obtained from solutions of the ibuprofen-conjugated prodrugs are summarized in relation to those of ibuprofen in water and in aqueous solutions of the original PEG, PN, and several ordinary surfactants. We believe that the fully hydrophilic PEG is completely hydrated and forms no hydrophobic pocket by segment aggregation. These results indicate that the probe environment is significantly hydrophobic, particularly in the solution of prodrug PN, for which the ratio is similar to that obtained from typical micelles of surfactants. The results suggest, therefore, that the present synthetic method is very useful for preparing PEG-based prodrugs from pharmaceuticals having carboxyl functionalities.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.204-210
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• 2007

Previous reports indicated that the carboxyl terminal residues, glutamine276-threonine277 in particular, were important for actin affinity of the unacetylated smooth ${\alpha}-tropomyosin$. To determine the role of the glutamine and threonine residues in C-terminal region in actin binding, we constructed mutant striated muscle ${\alpha}-tropomyosin$ (TMs), in which these two residues were individually substituted. These mutant tropomyosins, designated TM18 (HT) and TM19 (QA), were overexpressed in E. coli as an either unacetylated form or Ala-Ser. (AS) dipeptide fusion form, and were analyzed F-actin affinity by cosedimentation. Unacetylated TM19 (QA) bound to actin approximately three times stronger than TM18 (HT) and much stronger than ST (HA). AS/TM19 (QA) showed four times stronger, in actin affinity than AS/ST (HA) while AS/TM14 (QT) bound to actin stronger to some extent than AS/TM18 (HT). These results suggested that the presence of Gln residue at 276 be primarily attributed to higher actin affinity of smooth ${\alpha}-tropomyosin$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.4
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• pp.1037-1049
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• 2003

Numerous lines of evidence indicate that some of the neurotoxicity associated with Alzheimer's disease (AD) is due to proteolytic fragments of the amyloid precursor protein (APP). Most research has focused on the amyloid 6 (M). However, the possible role of other cleaved products of APP is less clear. Lately It has been reported that a recombinant carboxy-terminal 105 amino acid fragment (CT105) of APP induced strong nonselective inward currents in Xenopus oocyte. In a brain with Alzheimer's disease (AD), to investigate the roles of carboxyl-terminal fragment (CT105) of amyloid precursor protein (APP) in apoptosis processes possibly linked to neurodegeneration associated with AD, we examined the effects of the CT of APP with 105 amino acid residues (CT105) on the alteration of apoptosis triggers in neubroblastoma cells. We have investigated whether Radix Polygalae and Rhizoma Acori Graminei mixture extract (RP+RAG) inhibits CT105-induced apoptosis of neuroblastoma cells. We found that RP+RAG inhibits CT105-induced apoptosis in SK-N-SH cells. Treatment of the cells with RP+RAG inhibited CT105-induced DNA fragmentation and Tunel assay of nuclear chromatin and inhibited the caspase-3 expression in SK-N-SH cells. As the result of this study, In RP+RAG group, the apoptosis in the nervous system is inhibited, the repair against the degerneration of neuroblastoma cells by CT105 expression is promoted. These results indicate that RP+RAG possess strong inhibitory effect of apoptosis in the nervous system and repair effect against the degeneration of neuroblastoma cells by CT105 expression

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.276-280
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• 2000

In order to identify the domains of the G$_{\alpha}$16 subunit G protein that are responsible for its activation by the Interleukin-8 receptor, a serious of chimeras between G$_{\alpha}$16 and G$_{\alpha}$11 were assessed for their abilities to be activated by these receptors. Co-expression of IL-8 receptor and chimeras in which the carboxyl-terminal regions of G$_{\alpha}$11 were replaced from 30 up to 156 amino acid residues with the corresponding regions of G$_{\alpha}$16 demonstrated that C-terminal 156 amino acid residues of the G$_{\alpha}$16 were not sufficient to confer IL-8 receptor interaction specificity. Testing of a reciprocal serious of chimeras composed of G$_{\alpha}$16 sequences at the amino terminus and G$_{\alpha}$11 sequences at the carboxyl terminals revealed that sequences extending from the amino tar- minus to amino acid 209 of G$_{\alpha}$16 were sufficient to 7ndow the chimera with 75-80% of interaction specificity for 7-8-induced activation. These results suggest th,.7t combined interactions of the C-terminal 30 amino acid residues and certain domains extending from the arts.ino terminus to amino acid 209 of Gal 6 protein may be involved in its couplings to IL-8 receptor.tain domains extending from the arts.ino terminus to amino acid 209 of Gal 6 protein may be involved in its couplings to IL-8 receptor.

• Korean Journal of Animal Reproduction
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• v.26 no.4
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• pp.395-399
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• 2002

Human chorionic gonadotropin (hCG) is a member of the glycoprotein hormone family which includes FSH. hCG TSH. These hormone family is characterized by a heterodimeric structure composed a common $\alpha$-subunit noncovalently linked to a hormone specific $\beta$-subunit. To determine u and $\beta$ -subunits can be synthesized as a single polypeptide chain (tethered-hCG) and also display biological activity, the tethered-hCC and -FSH molecule by fusing the carboxyl terminus of the hCG $\beta$-subunit to the amino terminus of the $\alpha$-subunit was constructed. To determine the importance of $\alpha$ COOH -terminal amino acid, we also deleted the $\alpha$ COOH-terminal amino acids. The expressing vectors were transfected into CHO-K 1 cells. The tethered-wthCG and -wtFSH was efficiently secreted. The $\alpha$ Δ83hCG and $\alpha$ Δ 83FSH mutants had no secretion. These results are the first conclusive evidence that COOH-terminal amino acids are very important for secretion in human glycoprotein hormone $\alpha$-subunit. These results demonstrated that the $\alpha$ Δ83hCG and $\alpha$ Δ 83FSH mutants could be play a pivotal role in the secretion of tethered-molecule.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.73-80
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• 2023

Broad range of fatty acids were reported to show antimicrobial activities against broad range of microorganisms. However, possible changes of the antibacterial activity of a fatty acid based on structural variations are largely unknown. This study was focused on determination and comparison of the antimicrobial activities of the medium chain fatty acids, based on the position of carboxyl groups on either terminal end, against the representative food-pathogenic bacteria. Over all, mono-carboxyl medium chain fatty acids (MC-MCFA) presented stronger antimicrobial activities against the food-pathogenic bacteria tested including methicillin-resistant Staphylococcus aureus (MRSA) than di-carboxyl medium chain fatty acid (DC-MCFA). In addition, some of MC-MCFA and DC-MCFA showed high possibility to be used as a synergistic adjuvant for both the commercial β-lactam family antibiotics and aminoglycoside family antibiotics against MRSA.

• Proceedings of the Zoological Society Korea Conference
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• 2001.10a
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• pp.191.1-191
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• 2001

No Abstract, See Full Text