Proopiomelanocortin (POMC) is a precursor protein of several peptide hormones, such as ACTH and β-endorphin. Almost all of the peptide hormones in POMC have been drastically investigated in terms of ...their biological activities. However, the biological activity of the joining peptide region (JP) in POMC is unknown. Therefore, to explore the biological activity of JP, sequence analyses of mammalian POMC were performed. We found an -Arg-Gly-Asp- (RGD) motif in several mammalian species, such as porcine, suggesting that JP has cell adhesion activity. To validate this hypothesis, the cell adhesion activities of the synthetic porcine JP peptides were examined using 293T cells. Cell adhesions were observed in a concentration-dependent manner of the JP peptides. In addition, the JP peptide competitively inhibited cell adhesion to the POMC-coated plates. Moreover, the cell adhesion activity of the joining peptide was inhibited by the addition of EDTA, indicating that the JP peptide mediates the cell adhesion activity via a receptor protein, integrin. Interestingly, a human JP peptide, which possesses an -Arg-Ser-Asp- (RSD) sequence in place of the RGD sequence, exhibited a higher ability in the cell adhesion activity than that of the porcine JP peptide, suggesting that the cell adhesion activity of the joining peptide is developed during the molecular evolution of POMC. In conclusion, our results reveal that the joining peptide in POMC plays an important role during cell adhesion and provide useful information related to signal transduction of nerve peptide hormones derived from POMC.
Investigations of protein folding have largely involved the use of disulfide-containing proteins, since the disulfide-coupled folding of proteins allows folding intermediates to be trapped and their ...conformations determined. However, studies of the folding mechanisms of mid-size proteins face several problems, one of which is that detecting folding intermediates is difficult. Therefore, to solve this issue, a novel peptide reagent, maleimidohexanoyl-Arg
-Tyr-NH
, was designed and applied to the detection of folding intermediates of model proteins. BPTI was chosen as a model small protein to estimate the ability of the novel reagent to detect folding intermediates. In addition, a precursor protein (prococoonase) of
cocoonase was used as a model mid-size protein. Cocoonase is classified as a serine protease and has a high homology with trypsin. We recently found that the propeptide sequence of prococoonase (proCCN) is important for the folding of cocoonase. However, it was difficult to study the folding pathway of proCCN since the folding intermediates could not be separated on a reversed-phase HPLC (RP-HPLC). Therefore, to separate the folding intermediates by RP-HPLC, the novel labeling reagent was used to accomplish this for proCCN. The results indicated that the peptide reagent allowed the intermediates to be captured, separated on SDS-PAGE, and analyzed by RP-HPLC without the occurrence of undesirable disulfide-exchange reactions during the labeling reactions. The peptide reagent reported herein is a practical tool for investigating the mechanisms of disulfide-coupled folding of mid-size proteins.
Background
Dotinurad is a selective urate reabsorption inhibitor (SURI), which selectively inhibits URAT1 to lower serum uric acid levels in patients with hyperuricemia. Herein, the effects of ...dotinurad were compared among patient groups with different stages of renal dysfunction.
Methods
Patient data from four clinical trials were pooled and divided into four groups according to the stage of renal dysfunction to compare the effects of dotinurad at different stages. The grouping (stages G1–G3b) was based on the estimated glomerular filtration rate (eGFR) of the patients. In addition, patient data from a long-term study (34 or 58 weeks) were evaluated in the same manner.
Results
In the pooled analysis, the percentage of patients achieving a serum uric acid level of ≤ 6.0 mg/dL was 64.7–100.0% at a dose of 2 or 4 mg. In the long-term analysis, the percentage of patients achieving a serum uric acid level of ≤ 6.0 mg/dL was 60.0–100.0% at a dose of 2 or 4 mg. Although the outcomes in stage G3b were worse due to higher baseline serum uric acid levels, satisfactory outcomes were observed in all stages. Even in stages G3a and G3b, when renal function declined, the eGFR remained constant throughout the dose period.
Conclusion
The efficacy of dotinurad was confirmed in hyperuricemic patients with normal renal function (stage G1) and mild to moderate renal dysfunction (stage G2–G3b). Dotinurad was found to be effective in the treatment of hyperuricemia in patients with mild to moderate renal dysfunction.
Many studies have shown that microtubules (MTs) interact with MT-associated proteins and motor proteins. These interactions are essential for the formation and maintenance of the polarized morphology ...of neurons and have been proposed to be regulated in part by highly diverse, unusual post-translational modifications (PTMs) of tubulin, including acetylation, tyrosination, detyrosination, Δ2 modification, polyglutamylation, polyglycylation, palmitoylation, and phosphorylation. However, the precise mechanisms of PTM generation and the properties of modified MTs have been poorly understood until recently. Recent PTM research has uncovered the enzymes mediating tubulin PTMs and provided new insights into the regulation of MT-based functions. The identification of tubulin deacetylase and discovery of its specific inhibitors have paved the way to understand the roles of acetylated MTs in kinesin-mediated axonal transport and neurodegenerative diseases such as Huntington's disease. Studies with tubulin tyrosine ligase (TTL)-null mice have shown that tyrosinated MTs are essential in normal brain development. The discovery of TTL-like genes encoding polyglutamylase has led to the finding that polyglutamylated MTs which accumulate during brain development are involved in synapse vesicle transport or neurite outgrowth through interactions with motor proteins or MT-associated proteins, respectively. Here we review current exciting topics that are expected to advance MT research in the nervous system.
Coupling of thiol and urea-type -NHC(double bond, length as m-dashX)NH2 (X = O or NH) groups is effective in promoting oxidative protein folding. In particular, a thiol compound coupled with a ...guanidyl (X = NH) group significantly accelerates the rates of folding processes and enhances the yields of native proteins.
Background: Hyperuricemia is a risk factor for the development of hypertension and is comorbid in many hypertensive patients. According to Japanese hypertension management guidelines published in ...2019, a target serum uric acid level of ≤6.0 mg/dL is recommended in hypertensive patients with gout or asymptomatic hyperuricemia. Dotinurad is a novel uric acid-lowering drug classified as a selective urate reabsorption inhibitor. A pooled analysis was performed on the uric acid-lowering effect of dotinurad in 222 hypertensive patients with gout or asymptomatic hyperuricemia in four clinical trials (NCT02344862, NCT02416167, NCT03100318, NCT03372200). Moreover, we analyzed the long-term uric acid-lowering effect of dotinurad in 154 hypertensive patients with gout or asymptomatic hyperuricemia (NCT03006445).
Results: In the pooled analysis, the percent change in the decrease of serum uric acid with the use of dotinurad was 42.17 ± 12.42% at a dose of 2 mg and 60.42 ± 8.03% at a dose of 4 mg; the percentage of patients who achieved a serum uric acid level of ≤6.0 mg/dL was 82.8% and 100.0%. The long-term uric acid-lowering effect of dotinurad showed almost the same results. In this study, the concomitant use of diuretics or angiotensin II receptor blockers affected the uric acid-lowering effect of dotinurad at only a dose of 2 mg in the pooled analysis.
Conclusions: In the pooled analysis, dotinurad lowered serum uric acid levels. Dotinurad has an achievement rate of over 80% for serum uric acid level of ≤6.0 mg/dL in both analyses, and will be clinically useful for the management of hyperuricemic states in hypertensive patients.
Heat-stable enterotoxin (ST
) produced by Enterotoxigenic
is responsible for causing acute diarrhea in infants in developing countries. However, the chemical synthesis of ST
peptides with the native ...conformation and the correct intra-molecular disulfide bonds is a major hurdle for vaccine development. To address this issue, we herein report on the design and preparation of ST
analogs and a convenient chemical method for obtaining ST
molecules with the correct conformation. To develop an ST
vaccine, we focused on a structure in a type II β-turn in the ST
molecule and introduced a D-Lys residue as a conjugation site for carrier proteins. In addition, the -Glu-Leu- sequence in the ST
molecule was replaced with a -Asp-Val- sequence to decrease the toxic activity of the peptide to make it more amenable for use in vaccinations. To solve several issues associated with the synthesis of ST
, such as the formation of non-native disulfide isomers, the native disulfide pairings were regioselectively formed in a stepwise manner. A native form or topological isomer of the designed ST
peptide, which possesses a right-handed or a left-handed spiral structure, respectively, were synthesized in high synthetic yields. The conformation of the synthetic ST
peptide was also confirmed by CD and NMR spectroscopy. To further utilize the designed ST
peptide, it was labeled with fluorescein for fluorescent detection, since recent studies have also focused on the use of ST
for detecting cancer cells, such as Caco-2 and T84. The labeled ST
peptide was able to specifically and efficiently detect 293T cells expressing the recombinant ST
receptor (GC-C) protein and Caco-2 cells. The findings reported here provide an outline of the molecular basis for using ST
for vaccine development and in the detection of cancer cells.
Phacoemulsification has emerged as the global standard for cataract surgery, and various novel methods, tools, and agents have promoted surgical efficiency and reduced complications. Conventionally, ...the phaco tip, which cleaves and aspirates the cataractous lens, has been mainly constructed of metal. In this study, the risk of anterior capsule rupture was evaluated under conditions of different power modes, longitudinal (Mode-L), torsional (Mode-T), or both (Mode-LT), and different aspiration powers (0 or 200 mmHg), using a traditional metal phaco tip (Group-M) or a new phaco tip with a high-strength polymer overmold on the needle edge (Group-P), which was developed to reduce the risk of capsule rupture. One hundred twenty porcine eyes were used for experiments within a setting of typical human physiological intraocular pressure. We found that Group-M showed capsule rupture with a smaller ultrasound power than did Group-P, regardless of power mode or aspiration power. In Group-M, there was no significant difference in risk of capsule rupture among power modes, however in Group-P, capsule rupture was least likely to occur with Mode-T. These results provide useful information for inexperienced ophthalmologists to improve surgical safety.
Increased water intake is recommended for kidney transplant recipients; however, its efficacy remains controversial. We hypothesized that pre-existing histological findings of the allograft might ...modulate the impact of water intake. We retrospectively analyzed 167 adults with living-donor kidney transplants (April 2011-May 2020; median observation period, 77 months) whose baseline biopsy data were available. We compared the chronic-change group (n = 38) with the control group (n = 129) to assess the impact of self-reported daily water intake on the estimated glomerular filtration rate (eGFR). The range distribution of water intake was as follows: - 1000 ml (n = 4), 1000-1500 ml (n = 23), 1500-2000 ml (n = 64), 2000-2500 ml (n = 57), 2500-3000 ml (n = 16), and 3000 - ml (n = 3). Donor age was significantly higher in the chronic-change group. In the control group, the ΔeGFR/year increase was correlated with water intake. However, the increase in the water intake of the chronic-change group significantly decreased ΔeGFR/year (1000-1500 ml: + 1.95 ml/min/1.73 m
and > 2000 ml: - 1.92 ml/min/1.73 m
, p = 0.014). This study suggested a potential influence of increased water intake on recipients with marginal grafts in living donor kidney transplantation.
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