Sökresultat

Filtyp

Din sökning på "*" gav 534677 sökträffar

Single Residue on the WPD-Loop Affects the pH Dependency of Catalysis in Protein Tyrosine Phosphatases

Catalysis by protein tyrosine phosphatases (PTPs) relies on the motion of a flexible protein loop (the WPD-loop) that carries a residue acting as a general acid/base catalyst during the PTP-catalyzed reaction. The orthogonal substitutions of a noncatalytic residue in the WPD-loops of YopH and PTP1B result in shifted pH-rate profiles from an altered kinetic pK a of the nucleophilic cysteine. Compar

The N-terminal Helix-Turn-Helix Motif of Transcription Factors MarA and Rob Drives DNA Recognition

DNA-binding proteins play an important role in gene regulation and cellular function. The transcription factors MarA and Rob are two homologous members of the AraC/XylS family that regulate multidrug resistance. They share a common DNA-binding domain, and Rob possesses an additional C-terminal domain that permits binding of low-molecular weight effectors. Both proteins possess two helix-turn-helix

Heme-binding enables allosteric modulation in an ancient TIM-barrel glycosidase

Glycosidases are phylogenetically widely distributed enzymes that are crucial for the cleavage of glycosidic bonds. Here, we present the exceptional properties of a putative ancestor of bacterial and eukaryotic family-1 glycosidases. The ancestral protein shares the TIM-barrel fold with its modern descendants but displays large regions with greatly enhanced conformational flexibility. Yet, the bar

Divide and Surrender: Exploiting Variable Division Instruction Timing in HQC Key Recovery Attacks

We uncover a critical side-channel vulnerability in the Hamming Quasi-Cyclic (HQC) round 4 optimized implementation arising due to the use of the modulo operator. In some cases, compilers optimize uses of the modulo operator with compiletime known divisors into constant-time Barrett reductions. However, this optimization is not guaranteed: for example, when a modulo operation is used in a loop the

No title

Hjem (Home) is an exhibition showcasing the works of Sverre Bjertnæs, featuring around 40 paintings and sculptures, both old and new. The exhibition was curated by Fredrik Værslev in the spring of 2024. Bjertnæs is one of Norway's foremost painters and sculptors.

Ground-State Destabilization by Active-Site Hydrophobicity Controls the Selectivity of a Cofactor-Free Decarboxylase

Bacterial arylmalonate decarboxylase (AMDase) and evolved variants have become a valuable tool with which to access both enantiomers of a broad range of chiral arylaliphatic acids with high optical purity. Yet, the molecular principles responsible for the substrate scope, activity, and selectivity of this enzyme are only poorly understood to date, greatly hampering the predictability and design of

Modeling the Role of a Flexible Loop and Active Site Side Chains in Hydride Transfer Catalyzed by Glycerol-3-phosphate Dehydrogenase

Glycerol-3-phosphate dehydrogenase is a biomedically important enzyme that plays a crucial role in lipid biosynthesis. It is activated by a ligand-gated conformational change that is necessary for the enzyme to reach a catalytically competent conformation capable of efficient transition-state stabilization. While the human form (hlGPDH) has been the subject of extensive structural and biochemical

Enhancing a de novo enzyme activity by computationally-focused ultra-low-throughput screening

Directed evolution has revolutionized protein engineering. Still, enzyme optimization by random library screening remains sluggish, in large part due to futile probing of mutations that are catalytically neutral and/or impair stability and folding. FuncLib is a novel approach which uses phylogenetic analysis and Rosetta design to rank enzyme variants with multiple mutations, on the basis of predic

Semi-Secular Worldviews and the Belief in Something Beyond

An increasingly large part of the population in the West identifies as religious Nones. Contrary to what might be assumed, most of them are not outright atheists. They reject traditional religion, but many pursue different forms of spirituality, and many entertain supernatural ideas. This element concerns the worldview of these “semi-secular” Nones. When asked about whether they believe in God, th

Meanings of Identity of the Post-2000s Inland Tibet Class : An Interview with Jinyan Zeng

What identity does the post-2000s Inland Tibet Class (ITC) generation mean? How do Sinophone-Tibetan films articulate the expression of such identity? How does affective visuality mediate the cultural, political, and gender identity formation of female artists of the post-2000s ITC generation?Jinyan Zeng, a researcher at the Centre for East and South-East Asian Studies, Lund University, Sweden, in