Search results for "oligopeptides"
showing 10 items of 136 documents
Capping Parallel β-Sheets of Acetyl(Ala)6NH2 with an Acetyl(Ala)5ProNH2 Can Arrest the Growth of the Sheet, Suggesting a Potential for Curtailing Amy…
2014
We present ONIOM calculations using B3LYP/d95(d,p) as the high level and AM1 as the medium level on parallel β-sheets containing four strands of Ac-AAAAAA-NH2 capped with either Ac-AAPAAA-NH2 or Ac-AAAPAA-NH2. Because Pro can form H-bonds from only one side of the peptide linkage (that containing the C═O H-bond acceptor), only one of the two Pro-containing strands can favorably add to the sheet on each side. Surprisingly, when the sheet is capped with AAPAAA-NH2 at one edge, the interaction between the cap and sheet is slightly more stabilizing than that of another all Ala strand. Breaking down the interaction enthalpies into H-bonding and distortion energies shows the favorable interaction…
Sample pretreatment techniques for oligopeptide analysis from natural sources
2008
The analysis of oligopeptides in samples of food, tissues, and body fluids attracts considerable attention. The complexity of such samples requires efficient sample preparation (i.e., concentration and cleanup) procedures to remove interfering endogenous compounds and inorganic or organic salts. The methods of sample pretreatment that enable effective and selective isolation and/or preconcentration of oligopeptides from complex sample matrices have been reviewed. In each case, examples of application were presented and discussed, taking into account selectivity, enrichment, method automation, cleanup, and environmental aspects of the developed methods.
Triple therapy with first-generation Protease Inhibitors for patients with genotype 1 chronic hepatitis C: Recommendations of the Italian Association…
2013
AbstractThe first-generation Protease Inhibitors Boceprevir and Telaprevir administered in triple therapy regimens with Peg-interferon alpha and Ribavirin have been proven effective in increasing the rate of Sustained Virological Response in both naive and treatment-experienced patients with chronic genotype-1 hepatitis C. However, at the individual level, the therapeutic advantage of triple therapy is highly variable and results from the combination of multiple factors related to the characteristics of patient, viral status and liver disease.The recommendations presented are promoted by the Italian Association for the Study of the Liver, with the aim to help the physician in the decision-m…
Adjusted comparison between elotuzumab and carfilzomib in combination with lenalidomide and dexamethasone as salvage therapy for multiple myeloma pat…
2021
The lack of a randomized trial comparing carfilzomib (K) versus elotuzumab (Elo) associated with lenalidomide and dexamethasone (Rd) prompted us to assess the relative usefulness of one triplet over the other. Five independent retrospective cohorts of 883 relapsed/refractory multiple myeloma (RRMM) patients, including 300 EloRd and 583 KRd cases, outside clinical trials, entered this non-randomized comparison. KRd cohort accounted for a higher incidence of younger patients, cases with ≥3 lines of therapy, already exposed to lenalidomide, International Staging System (ISS) stage III, and abnormal lactic dehydrogenase (LDH) level compared with EloRd cohort. Moreover, cytogenetic risk categori…
Antimetastatic activity of adriamycin in combinations with proteinase inhibitors in mice
1990
The antimetastatic activity of adriamycin in combination with proteinase inhibitors was investigated in mice bearing the metastatic tumors L1210 leukemia, Lewis lung carcinoma or M5076 sarcoma. Leupeptin, a cathepsin B inhibitor, when administered as a single agent was devoid of antimetastatic activity but some therapeutic activity was noted in mice with Lewis lung carcinoma when the agent was administered in combination with adriamysin. Pepstatin A, a cathepsin D inhibitor, had no effect as a single agent in mice with L1210 leukemia but displayed some antimetastatic activity in mice with Lewis lung carcinoma. In mice with M5076 sarcoma the combination of pepstatin A and adriamycin resulted…
Kinetics of in vivo inhibition of tissue cathepsin d by pepstatin A
1988
1. 1. We have investigated the kinetics of inhibition of cathepsin D in heart, liver and skeletal muscle of CD-1 mice following administration of 25, 50, 100 and 200 mg/kg i.p. of pepstatin A, a specific inhibitor of this protease. 2. 2. In the liver, a significant inhibition of cathepsin D occurred up to at least 15 days, whereas, in heart and skeletal muscle, this inhibition lasted for a much shorter period of time. 3. 3. These results show that the recovery of enzyme activity to normal values is dose-dependent and that, at the same dose level, marked differences occur in the recovery of enzyme activity in these organ tissues, the liver being the most sensitive one. © 1988.
Phosphorylation of GAP-43 (growth-associated protein of 43 kDa) by conventional, novel and atypical isotypes of the protein kinase C gene family: dif…
1996
GAP-43 (growth-associated protein of 43 kDa; also known as neuromodulin, P-57, B-50 and F-1) is a neuronal calmodulin binding protein and a major protein kinase C (PKC) substrate in mammalian brain. Here we describe the phosphorylation by and the site specificity of different PKC isotypes. The conventional PKC beta 1 and the novel PKCs delta and epsilon effectively phosphorylated recombinant GAP-43 in vitro; atypical PKC zeta did not. The K(m) values (between 0.6 and 2.3 microM) were very low, demonstrating a high-affinity interaction between kinase and substrate. All PKC isotypes were shown to phosphorylate serine-41 in GAP-43. When using a 19-amino-acid oligopeptide based on the GAP-43 ph…
Progress in the characterization of insulin-like peptides in aphids: Immunohistochemical mapping of ILP4.
2021
Aphids were the first animals described as photoperiodic due to their seasonal switch from viviparous parthenogenesis to sexual reproduction (cyclical parthenogenesis) caused by the shortening of the photoperiod in autumn. This switch produces a single sexual generation of oviparous females and males that mate and lay diapausing cold-resistant eggs that can overcome the unfavourable environmental conditions typical of winter in temperate regions. Previous studies have hinted at a possible implication of two insulin-like peptides (ILP1 and ILP4) in the aphid seasonal response, changing their expression levels between different photoperiodic conditions. Moreover, in situ localization of their…
Learning from nature: beta-sheet-mimicking copolymers get organized.
2007
The solution structures formed by coil-coil copolymers arise from the selective solvation of one of the two blocks and have been well described. In most cases in such relatively simple synthetic structures there are no specific attractive forces that can aid the aggregation process. Nature, however, provides plenty of inspiring polymeric architectures that are shaped and ordered hierarchically by noncovalent forces. The high level of structural definition displayed by proteins, for example, is unmatched by synthetic polymers. An emerging area of interest in polymer science tries to combine the best of both worlds, the natural and the synthetic, by conjugating synthetic polymers and beta-she…
Hepatitis C Virus NS3/4A Protease Inhibitors.
2008
Chronic hepatitis C virus infection is a global problem worldwide due to the lack of an effective therapy (the current standard of care treatment is effective in about 40-50% of the cases), and the difficulties in developing a protective vaccine. Chronic infection progresses to end-stage liver disease and liver failure in a considerable number of infected individuals. Once liver function is compromised, the only reliable therapeutic intervention is liver transplantation. Unfortunately, re-infection of the graft is unavoidable, and a new chronic hepatitis is early established in transplant recipients, that can result in graft loss. Thus, there is an urgent need for new, specifically targeted…