Development Automobile Engine Hood Latch

V diplomové práci se zabývá konstrukčním návrhem automobilového zámku, který má hlavní komponenty v „plastovém“ provedení (rohatka, západka, tělesa). Tyto plastové díly jsem vhodně navrhl a optimalizoval na požadované zatížení. Zároveň srovnávám plastový zámek a ocelový zámek přední kapoty, srovnávám jak cenu zámků, tak hmotnost a zatížení zámků. V krátkosti porovnávám automobilové zámky přední kapoty v současném automobilovém průmyslu. Také se zabývám etapou výroby prototypového vzorku v současnosti.The diploma thesis deals with the design of the car lock, which main components such as claw, pawl and housing are made of plastic. My main goal was to optimized these plastic parts for a certain amount of power. The following part shows a comparison of plastic lock and the steel lock of front bonnet. The following part shows a comparison of the plastic lock and the steel lock of the front bonnet. The comparison is made in terms of the price, weight and load of the locks. The diploma thesis also briefly deals with the comparison of car locks of car locks of front bonnets in the current automotive industry and the stage of prototype sample production nowadays.340 - Katedra výrobních strojů a konstruovánívelmi dobř

RI-MP2 Gradient Calculation of Large Molecules Using the Fragment Molecular Orbital Method

The second-order Møller–Plesset perturbation theory (MP2) gradient using resolution of the identity approximation (RI-MP2 gradient) was combined with the fragment molecular orbital (FMO) method to evaluate the gradient including electron correlation for large molecules. In this study, we adopted a direct implementation of the RI-MP2 gradient, in which a characteristic feature of the FMO scheme was utilized. Test calculations with a small peptide presented a computational advantage of the RI-MP2 gradient over the canonical MP2 gradient. In addition, it was shown that the error of the RI-MP2 gradient, caused by RI approximation, was negligible. As an illustrative example, we performed gradient calculations for two biomoleculesa prion protein with GN8 and a human immunodeficiency virus type 1 (HIV1) protease with lopinavir (LPV). These calculations demonstrated that the gradient including the correlation effect could be evaluated with only about twice the computational effort of the Hartree–Fock (HF) gradient

Protein–Ligand Dissociation Simulated by Parallel Cascade Selection Molecular Dynamics

We investigated the dissociation process of tri-<i>N</i>-acetyl-d-glucosamine from hen egg white lysozyme using parallel cascade selection molecular dynamics (PaCS-MD), which comprises cycles of multiple unbiased MD simulations using a selection of MD snapshots as the initial structures for the next cycle. Dissociation was significantly accelerated by PaCS-MD, in which the probability of rare event occurrence toward dissociation was enhanced by the selection and rerandomization of the initial velocities. Although this complex was stable during 1 μs of conventional MD, PaCS-MD easily induced dissociation within 10⁰–10¹ ns. We found that velocity rerandomization enhances the dissociation of triNAG from the bound state, whereas diffusion plays a more important role in the unbound state. We calculated the dissociation free energy by analyzing all PaCS-MD trajectories using the Markov state model (MSM), compared the results to those obtained by combinations of PaCS-MD and umbrella sampling (US), steered MD (SMD) and US, and SMD and the Jarzynski equality, and experimentally determined binding free energy. PaCS-MD/MSM yielded results most comparable to the experimentally determined binding free energy, independent of simulation parameter variations, and also gave the lowest standard errors

Synthesis of double-fluorescent labeled prion protein for FRET analysis

<div><p>An abnormal form of prion protein (PrP) is considered to be the pathogen in prion diseases. However, the structural details of this abnormal form are not known. To characterize the non-native structure of PrP, we synthesized position-specific double-fluorescent labeled PrP for a fluorescence resonance energy transfer (FRET) experiment. Using FRET, we observed a conformational change in the labeled PrP associated with amyloid fibril formation. The FRET analysis indicated that the distance between fluorescent labeled N- and C-terminal sites of PrP increased upon the formation of amyloid fibrils compared with that of the native state. This approach using FRET analysis is useful for elucidating the structure of abnormal PrP.</p></div

Nearly Reversible Conformational Change of Amyloid Fibrils as Revealed by pH-Jump Experiments

pH-jump induced conformational transitions between substates of preformed amyloid fibrils made by a fragmented peptide of helix 2 (H2 peptide) of MoPrP were detected, and their kinetics were analyzed using a novel pH-jump apparatus specially designed for observing amyloids. Previously, we reported that H2 peptide formed ordered fibrils with a minimum at 207 nm on CD spectra at pH 2.9 (named pH 2.9 fibrils), but formed aggregate-like fibrils with a minimum at 220 nm at pH 7.5 (named pH 7.5 fibrils). When pH-jump from 2.9 to 7.5 was performed, the CD spectrum changed instantly, but the finally observed ellipticities were clearly distinct from those of pH 7.5 fibrils. Thus, the finally observed state is termed ‘pH 7.5-like fibrils’. However, pH 7.5-like fibrils reverted to the conformation very similar to that of the pH 2.9 fibrils when the pH of the solution was restored to 2.9. Then, we examined the kinetics of the nearly reversible conformational changes between pH 2.9 fibrils and pH 7.5-like fibrils using ANS fluorescence stopped-flow, and we observed relatively fast phases (0.7–18 s^–1). In contrast, the conversion between pH 7.5-like fibrils and pH 7.5 fibrils never occurred (<0.2 day^–1). Thus, H2 fibrils can be switched readily between distinct conformations separated by a low energy barrier, while a large energy barrier clearly separated the different conformations. These conformational varieties of amyloid fibrils may explain the physical basis of the diversity in prion

Synthesis of Potent and Selective Inhibitors of Aldo-Keto Reductase 1B10 and Their Efficacy against Proliferation, Metastasis, and Cisplatin Resistance of Lung Cancer Cells

Aldo-keto reductase 1B10 (AKR1B10) is overexpressed in several extraintestinal cancers, particularly in non-small-cell lung cancer, where AKR1B10 is a potential diagnostic marker and therapeutic target. Selective AKR1B10 inhibitors are required because compounds should not inhibit the highly related aldose reductase that is involved in monosaccharide and prostaglandin metabolism. Currently, 7-hydroxy-2-(4-methoxyphenylimino)-2<i>H</i>-chromene-3-carboxylic acid benzylamide (HMPC) is known to be the most potent competitive inhibitor of AKR1B10, but it is nonselective. In this study, derivatives of HMPC were synthesized by removing the 4-methoxyphenylimino moiety and replacing the benzylamide with phenylpropylamide. Among them, <b>4c</b> and <b>4e</b> showed higher AKR1B10 inhibitory potency (IC₅₀ 4.2 and 3.5 nM, respectively) and selectivity than HMPC. The treatments with the two compounds significantly suppressed not only migration, proliferation, and metastasis of lung cancer A549 cells but also metastatic and invasive potentials of cisplatin-resistant A549 cells

A Novel Potent and Highly Specific Inhibitor against Influenza Viral N1–N9 Neuraminidases: Insight into Neuraminidase–Inhibitor Interactions

People throughout the world continue to be at risk for death from influenza A virus, which is always creating a new variant. Here we present a new effective and specific anti-influenza viral neuraminidase (viNA) inhibitor, 9-cyclopropylcarbonylamino-4-guanidino-Neu5Ac2en (cPro-GUN). Like zanamivir, it is highly effective against N1–N9 avian and N1–N2 human viNAs, including H274Y oseltamivir-resistant N1 viNA, due to its C-6 portion still being anchored in the active site, different from the disruption of oseltamivir’s C-6 anchoring by H274Y mutation. Unlike zanamivir, no sialidase inhibitory activity has been observed for cPro-GUN against huNeu1-huNeu4 enzymes. Broad efficacy of cPro-GUN against avian and human influenza viruses in cell cultures comparable to its sialidase inhibitory activities makes cPro-GUN ideal for further development for safe therapeutic or prophylactic use against both seasonal and pandemic influenza