Hasil untuk "Biochemistry"

E. Paul

J. Endicott, V. Ling

B. Halliwell

N. Keller, G. Turner, J. Bennett

T. Holton, E. Cornish

G. Rubanyi, M. Polokoff

R. Dean, S. Fu, R. Stocker et al.

R. Visse, Hideaki Nagase

D. Vance, J. Vance

1. Physical Properties and Functional Roles of Lipids in Membranes (Pieter R. Cullis and Michael J. Hope). 2. Lipid Metabolism in Procaryotes (Suzanne Jackowski, John E. Cronan, Jr. and Charles O. Rock). 3. Oxidation of Fatty Acids (Horst Schulz) 4. Fatty Acid Synthesis in Eucaryotes (Alan G. Goodridge). 5. Fatty Acid Desaturation and Chain Elongation in Eucaryotes (Harold W. Cook). 6. Metabolism of Triacylglycerols (David N. Brindley) 7. Phospholipid Metabolism and Cell Signaling in Eucaryotes (Dennis E. Vance) 8. Metabolism, Regulation and Function of Ether-linked Glycerolipids and their Bioactive Species (Fred Snyder). 9. Phospholipases (Moseley Waite). 10. The Eicosanoids: Cyclooxygenase, Lipoxygenase and Epoxygenase Pathways (William L. Smith, Pierre Borgeat and Frank A. Fitzpatrick). 11. Sphingolipids (Charles C. Sweeley). 12. Cholesterol: Evolution of Structure and Function (Konrad Bloch). 13. Regulation of Sterol Biosynthesis and Isoprenylation of Proteins (Peter A. Edwards). 14. Lipoprotein Structure and Secretion (Roger Davis). 15. Dynamics of Lipoprotein Transport in the Circulatory System (Christopher J. Fielding and Phoebe E. Fielding). 16. Removal of Lipoproteins from Plasma (Wolfgang J. Schneider). 17. Lipid Assembly in Cell Membranes (Dennis R. Voelker). 18. Assembly of Proteins into Membranes (Reinhart A.F. Reithmeier).

R. Robergs, F. Ghiasvand, D. Parker

J. Lumsden

E. Grotewold

C. Wasternack, I. Feussner

I. Denisov, S. Sligar

Geoff P. Horsman, D. Zechel

Nicholas J. Barrows, Nicholas J. Barrows, R. K. Campos et al.

Jonathan A Stefely, D. Pagliarini

B. Kuai, Junyi Chen, S. Hörtensteiner

Chlorophyll breakdown is one of the most obvious signs of leaf senescence and fruit ripening. The resulting yellowing of leaves can be observed every autumn, and the color change of fruits indicates their ripening state. During these processes, chlorophyll is broken down in a multistep pathway, now termed the 'PAO/phyllobilin' pathway, acknowledging the core enzymatic breakdown step catalysed by pheophorbide a oxygenase, which determines the basic linear tetrapyrrole structure of the products of breakdown that are now called 'phyllobilins'. This review provides an update on the PAO/phyllobilin pathway, and focuses on recent biochemical and molecular progress in understanding phyllobilin-modifying reactions as the basis for phyllobilin diversity, on the evolutionary diversity of the pathway, and on the transcriptional regulation of the pathway genes.

Julian Beck, Sergio Romero-Romero

The TIM-barrel fold is one of the most versatile and ubiquitous protein folds in nature, hosting a wide variety of catalytic activities and functions while serving as a model system in protein biochemistry and engineering. This review explores its role as a key fold model in protein design, particularly in addressing challenges in stabilization and functionalization. We discuss historical and recent advances in de novo TIM barrel design from the landmark creation of sTIM11 to the development of the diversified variants, with a special focus on deepening our understanding of the determinants that modulate the sequence-structure-function relationships of this architecture. Also, we examine why the diversification of de novo TIM barrels towards functionalization remains a major challenge, given the absence of natural-like active site features. Current approaches have focused on incorporating structural extensions, modifying loops, and using cutting-edge AI-based strategies to create scaffolds with tailored characteristics. Despite significant advances, achieving enzymatically active de novo TIM barrels has been proven difficult, with only recent breakthroughs demonstrating functionalized designs. We discuss the limitations of stepwise functionalization approaches and support an integrated approach that simultaneously optimizes scaffold structure and active site shape, using both physical- and AI-driven methods. By combining computational and experimental insights, we highlight the TIM barrel as a powerful template for custom enzyme design and as a model system to explore the intersection of protein biochemistry, biophysics, and design.

John F. Malloy, Camerian Millsaps, Kamesh Narasimhan et al.

Molecular chirality is critical to biochemical function, but it is unknown when chiral selectivity first became important in the evolutionary transition from geochemistry to biochemistry during the emergence of life. Here, we identify key transitions in the selection of chiral molecules in metabolic evolution, showing how achiral molecules (lacking chiral centers) may have given rise to specific and abundant chiral molecules in the elaboration of metabolic networks from geochemically available precursor molecules. Simulated expansions of biosphere-scale metabolism suggest new hypotheses about the evolution of chiral molecules within biochemistry, including a prominent role for both achiral and chiral compounds as nucleation sites of early metabolic network growth, an increasing enrichment of molecules with more chiral centers as these networks expand, and conservation of broken chiral symmetries along reaction pathways as a general organizing principle. We also find an unexpected enrichment in large, non-polymeric achiral molecules. Leveraging metabolic data of 40,023 genomes and metagenomes, we analyzed the statistics of chiral and achiral molecules in the large-scale organization of metabolism, revealing a chiral-enriched phase of network organization evidenced by system-size dependent chiral scaling laws that differ for individuals and ecosystems. By uncovering how metabolic networks could lead to chiral selection, our findings open new avenues for bridging metabolism and genetics-first approaches to the origin of chirality, allowing tools for better timing of major transitions in molecular organization during the emergence of life, understanding the role of chirality in extant and synthetic metabolisms, and informing targets for chirality-based biosignatures.