ABSTRACT
End-capped peptides modified with reactive functional groups on the N-terminus provide a route to prepare peptide-polymer conjugates for a broad range of applications. Unfortunately, current chemical methods to construct modified peptides rely largely on solid-phase peptide synthesis (SPPS), which lacks green preparative characteristics and is costly, thus limiting its applicability to specialty applications such as regenerative medicine. This work evaluates N-terminally modified N-acryloyl-glutamic acid diethyl ester, N-acryloyl-leucine ethyl ester, and N-acryloyl-alanine ethyl ester as grafters and papain as the protease for the direct addition of amino acid ethyl ester (AA-OEt) monomers via protease-catalyzed peptide synthesis (PCPS) and the corresponding formation of N-acryloyl-functionalized oligopeptides in a one-pot aqueous reaction. It was hypothesized that by building N-acryloyl grafters from AA-OEt monomers that are known to be good substrates for papain in PCPS, the corresponding grafters would yield high grafter conversions, high ratio of grafter-oligopeptide to free NH2-oligopeptide, and high overall yield. However, this work demonstrates based on the grafter/monomers studied herein that the dominant factor in N-acryloyl-AA-OEt grafter conversion is the co-monomer used in co-oligomerizations. Computational modeling using Rosetta qualitatively recapitulates the results and provides insight into the structural and energetic bases underlying substrate selectivity. The findings herein expand our knowledge of factors that determine the efficiency of preparing N-acryloyl-terminated oligopeptides by PCPS that could provide practical routes to peptide macromers for conjugation to polymers and surfaces for a broad range of applications.
Subject(s)
Amino Acids , Peptide Hydrolases , Papain/chemistry , Peptides/chemistry , Oligopeptides/chemistry , Polymers , Catalysis , EstersABSTRACT
PURPOSE: The purpose of this study was to inspect the interactions between an anti-breast cancer, TAM, with model of lipid membranes composed of either zwitterionic DPPC LUVs or anionic DPPG LUVs and how they depend on ionic strength and cholesterol. METHODS: The Kp of TAM into DPPC and DPPG LUVs were determined at three different NaCl concentrations by second derivative UV-Vis spectrophotometry. The effect of cholesterol incorporated into these LUVs on TAM's Kp was also assessed. The ATR-FTIR measurements were carried out to verify structural changes within the acyl chain and head group regions of the liposomes upon TAM partitioning. RESULTS: Increasing salt concentration produced negligible impact on the partitioning of TAM into DPPC bilayer as its Kp remained unaffected whilst induced outstanding reduction of TAM's Kp into DPPG liposomes. Furthermore, TAM was found to disorder the lipids' acyl chains, which could result in an increase in the membrane fluidity, a necessary piece of information to refer to when prescribing TAM dosage for administration. Additionally, cholesterol showed astoundingly opposite contribution to the partitioning of TAM into the LUVs, as its Kp value reduced in DPPC/Chol bilayer yet increased in DPPG/Chol liposomes. CONCLUSION: Ionic strength and cholesterol play a noteworthy role in regulation of TAM partitioning into lipid membranes as they could obstruct or promote such action.
Subject(s)
Cholesterol/chemistry , Membrane Lipids/chemistry , Osmolar Concentration , Tamoxifen/chemistry , 1,2-Dipalmitoylphosphatidylcholine/analogs & derivatives , 1,2-Dipalmitoylphosphatidylcholine/chemistry , Cell Membrane/drug effects , Molecular Structure , Phosphatidylglycerols/chemistry , Tamoxifen/metabolism , Tamoxifen/pharmacologyABSTRACT
Introduction: To explore the feasibility and safety of retroperitoneal laparoscopic partial nephrectomy (RLPN) with selective artery clamp (SAC) in patients with renal cell carcinoma (RCC). Methods: The authors recruited three men and two women who underwent RLPN for T1 RCC between December 2022 and May 2023 at a tertiary hospital. The median age of the patients was 32 years (range, 25-70 years). The tumour size ranged from 3 to 4.5 cm. The R.E.N.A.L scores were 4x, 5p, 8a, 5a, and 8ah. The median preoperative eGFR was 96.9 (74.3-105.2). Renal computed tomography angiography was performed before the surgery to evaluate the artery branches. The operation time, number of clamped arteries, warm ischaemic time (WIT), intraoperative blood loss, RCC type, postoperative hospital stay, changes in renal function, and complications were evaluated. The follow-up duration was 6 months. Results: The median operation time was 120 (75-150) minutes. One artery was clamped in four patients, while three were clamped in one patient. The median WIT was 22 (15-30) min, and the median blood loss was 150 (100-300) ml. No complications were recorded, and the resection margin was negative in all patients. The median decrease in eGFR was 6 (4-30%). Conclusions: RLPN with SAC for T1 RCC is safe and feasible in clinical practice.
ABSTRACT
Color patterns in nonavian reptiles are beautifully diverse, but little is known about the genetics and development of these patterns. Here, we investigated color patterning in pet ball pythons (Python regius), which have been bred to show color phenotypes that differ dramatically from the wildtype form. We report that several color phenotypes in pet animals are associated with putative loss-of-function variants in the gene encoding endothelin receptor EDNRB1: (1) frameshift variants in EDNRB1 are associated with conversion of the normal mottled color pattern to skin that is almost fully white, (2) missense variants affecting conserved sites of the EDNRB1 protein are associated with dorsal, longitudinal stripes, and (3) substitutions at EDNRB1 splice donors are associated with subtle changes in patterning compared to wildtype. We propose that these phenotypes are caused by loss of specialized color cells (chromatophores), with loss ranging from severe (fully white) to moderate (dorsal striping) to mild (subtle changes in patterning). Our study is the first to describe variants affecting endothelin signaling in a nonavian reptile and suggests that reductions in endothelin signaling in ball pythons can produce a variety of color phenotypes, depending on the degree of color cell loss.
Subject(s)
Boidae , Animals , Mutation, Missense , EndothelinsABSTRACT
Background: While depression is a common mental disorder, the diagnosis of this condition is still challenging. Thus, there is a need to have a validated tool to help evaluate symptoms of depression. This study aimed to evaluate the reliability and validity of the Vietnamese version of the Hamilton D-17 scale. Methods: A cross-sectional, descriptive, and validation study was conducted on 183 patients including 139 depressed and 44 non-depressed patients at the University Medical Center of Medicine and Pharmacy University at Ho Chi Minh City. Internal reliability and inter-rater reliability was measured using Cronbach's alpha and intraclass correlation coefficients (ICC). Confirmatory factor analysis (CFA) was used to evaluate construct validity. The Patient Health Questionnaire (PHQ9) was used to measure concurrent validity of the Hamilton D-17. Area under the ROC curve was used to measure criterion validity. Results: Both Cronbach alpha coefficient and ICC were at good level at alpha = 0.83 and ICC = 0.83. CFA with a second-order model consisting of four factors fitted the data at good to excellent level. The SRMR (Standardized Root Mean Squared Residual) was 0.066, RMSEA (Root Mean Square Error of Approximation) (90% CI) was 0.053 (0.036-0.069), CFI (comparative fit index) was 0.93, TLI (Tucker Lewis index) was 0.92. The Hamilton D-17 and the PHQ-9 had a correlation coefficient of r = 0.77 (p < 0.001). The Hamilton D-17 had a very high level of criterion validity with AUC of 0.93 (0.88-0.98). Conclusion: The Vietnamese version of the Hamilton D-17 scale has a high level of validity and reliability. The scale should be used to assess symptoms of depression among Vietnamese patients.
ABSTRACT
Melanophilin is a myosin adaptor required for transporting the pigment melanin within cells. Loss of melanophilin in fish, birds, and mammals causes pigmentation defects, but little is known about the role of melanophilin in non-avian reptiles. Here we show that a frameshift in the melanophilin gene in ball python ( P. regius ) is associated with loss of pigment from shed skin. This variant is predicted to remove the myosin-binding domain of melanophilin and thereby impair transport of melanin-containing organelles. Our study represents the first description of a melanophilin variant in a non-avian reptile and confirms the role of melanophilin across vertebrates.
ABSTRACT
Circadian rhythms broadly regulate physiological functions by tuning oscillations in the levels of mRNAs and proteins to the 24-h day/night cycle. Globally assessing which mRNAs and proteins are timed by the clock necessitates accurate recognition of oscillations in RNA and protein data, particularly in large omics data sets. Tools that employ fixed-amplitude models have previously been used to positive effect. However, the recognition of amplitude change in circadian oscillations required a new generation of analytical software to enhance the identification of these oscillations. To address this gap, we created the Pipeline for Amplitude Integration of Circadian Exploration suite. Here, we demonstrate the Pipeline for Amplitude Integration of Circadian Exploration suite's increased utility to detect circadian trends through the joint modeling of the Mus musculus macrophage transcriptome and proteome. Our enhanced detection confirmed extensive circadian posttranscriptional regulation in macrophages but highlighted that some of the reported discrepancy between mRNA and protein oscillations was due to noise in data. We further applied the Pipeline for Amplitude Integration of Circadian Exploration suite to investigate the circadian timing of noncoding RNAs, documenting extensive circadian timing of long noncoding RNAs and small nuclear RNAs, which control the recognition of mRNA in the spliceosome complex. By tracking oscillating spliceosome complex proteins using the PAICE suite, we noted that the clock broadly regulates the spliceosome, particularly the major spliceosome complex. As most of the above-noted rhythms had damped amplitude changes in their oscillations, this work highlights the importance of the PAICE suite in the thorough enumeration of oscillations in omics-scale datasets.
Subject(s)
Circadian Clocks , Spliceosomes , Animals , Circadian Clocks/genetics , Circadian Rhythm/genetics , Gene Expression Regulation , Macrophages/metabolism , Mice , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Untranslated , Spliceosomes/genetics , Spliceosomes/metabolismABSTRACT
Molecular interaction between the antidepressant fluoxetine and lipid bilayers was investigated in order to provide insights into the drug's incorporation to lipid membranes. In particular, the effects of lipid's unsaturation degree and cholesterol content on the partitioning of fluoxetine into large unilamellar vesicles (LUVs) comprised of unsaturated 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and saturated 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) were evaluated using second derivative spectrophotometry and Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). It was found that fluoxetine partitioned to a greater extent into the liquid-crystalline DOPC LUVs than into the solid-gel DPPC LUVs. The lipid physical state dependence of drug partitioning was verified by increasing the temperature in which the partition coefficient of fluoxetine significantly increased upon the change of the lipid phase from solid-gel to liquid-crystalline. The incorporation of 28mol% cholesterol into the LUVs exerted a significant influence on the drug partitioning into both DOPC and DPPC LUVs. The ATR-FTIR study revealed that fluoxetine perturbed the conformation of DOPC more strongly than that of DPPC due to the cis-double bonds in the lipid acyl chains. Fluoxetine possibly bound to the carbonyl moiety of the lipids through the hydrogen bonding formation while displaced some water molecules surrounding the PO2- regions of the lipid head groups. Cholesterol, however, could lessen the interaction between fluoxetine and the carbonyl groups of both DOPC and DPPC LUVs. These findings provided a better understanding of the role of lipid structure and cholesterol on the interaction between fluoxetine and lipid membranes, shedding more light into the drug's therapeutic action.
Subject(s)
Fluoxetine/chemistry , Lipid Bilayers/chemistry , Lipids/chemistry , Buffers , Cholesterol/chemistry , Molecular Conformation , Solutions , Spectroscopy, Fourier Transform Infrared , VibrationABSTRACT
The interaction between a drug molecule and lipid bilayers is highly important regarding the pharmaceutical activity of the drug. In this study, the interaction of fluoxetine, a well-known selective serotonin reuptake inhibitor antidepressant and lipid bilayers composed of 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) was studied from the aspect of electrostatics using second derivative spectrophotometry and Fourier transform infrared spectroscopy (FTIR) in order to provide insights into the drug behavior. Changing pH from 7.4 to 9.5 to increases the neutral state of fluoxetine, the partitioning of fluoxetine into the zwitterionic DPPC large unilamellar vesicles (LUVs) was increased whereas it was reduced into the negatively charged DPPG LUVs. Fluoxetine was found to exhibit a disordering effect on the acyl chains of DPPC and DPPG bilayers upon its partitioning. In addition, increasing concentration of NaCl lessened the binding of fluoxetine into DPPG bilayers due to the reduction in electrostatic attraction between positively charged fluoxetine and negatively charged DPPG LUVs. In addition, the FTIR study revealed that increasing the NaCl concentration could trigger the shift to higher frequency of the CH2 stretching as well as the notable blue shift in the PO2- regions of DPPG, indicating that fluoxetine had deeper penetration into DPPG LUVs. The differences in the NaCl concentration showed a negligible effect on the incorporation of fluoxetine into the zwitterionic DPPC LUVs. In summary, the electrostatic interaction plays an important role on the partitioning of a cationic amphiphilic SSIR drug into the lipid bilayers and the drug partitioning induces the lipids' conformational change. These imply a possible influence on the drug pharmacology.