生物化学技术

RNA polymerase (RNAP) is a DNA-dependent motor protein that links ribonucleotide polymerization to force generation and DNA translocation through its active site, i.e., mechanical work. Single-molecule studies using optical tweezers have allowed researchers to probe the load- ...

Almost all aspects of DNA metabolism involve separation of double-stranded DNA catalyzed by helicases. Observation and measurement of the dynamics of these events at the single-molecule level provide important mechanistic details of helicase activity and give the opportunity to ...

The dynamics of full protein synthesis and the co-translational folding processes are not fully understood. We have developed a novel method, using a combination of ribosome display and single-molecule techniques, for monitoring the synthesis, co-translational folding, and matu ...

Eukaryotic chromosomes are highly packed into chromatin, the basic unit of which is the nucleosome. The presence of nucleosomes and the resulting organization of the genome into higher-order chromatin structures has profound consequences for virtually all aspects of DNA metaboli ...

Magnetic tweezers provide a versatile tool enabling the precise application of force and torque on �individual biomolecules. These properties make magnetic tweezers uniquely suited for the study of DNA topology and topoisomerases at the single-molecule level. Single-molecule ...

PC1/3 is a neuroendocrine-specific member of the mammalian subtilisin-like proprotein convertase family. This seven-member family is involved in the endoproteolytic cleavage of a large number of precursor proteins including prohormones, proneuropeptides, zymogens, and p ...

Epigenetic alterations produce heritable changes in phenotype or gene expression without changing DNA sequence. Modified levels of gene expression contribute to a variety of human diseases encompassing genetic disorders, pediatric syndromes, autoimmune disease, aging, a ...

7B2 is a chaperone for the prohormone/proneuropeptide convertase PC2. Its mRNA is readily detectable in most neuronal and endocrine cells; the protein, in contrast, is often found at relatively low levels, suggesting that translation of the corresponding mRNA may be repressed. Because t ...

In addition to the large spectrum of the protein precursors processed and activated by the proprotein convertases (PCs) that are crucial for the maintenance of the malignant phenotype of colon cancer cells such as matrix metalloproteases, adhesion molecules, growth factors, and growth ...

Post-translational modification(s) can affect a protein’s function – changing its half-life/stability, its protein–protein interactions, biological activity and/or sub-cellular localization. Following translation, a protein can be modified in several ways, including ...

Proprotein convertases represent an important class of biosynthetic enzymes that are increasingly viewed as targets for therapeutic approaches to infection, cancer, and potentially endocrine disorders. The identification of potent inhibitors can be accomplished by scre ...

The mammalian proprotein convertase subtilisin kexins (PCSKs) previously called proprotein or prohormone convertases (PCs) are a family of Ca+2-dependent endoproteases in the subtilisin family. These proteolytic enzymes exert their many crucial physiological and biolo ...

Neuropeptides are essential for cell–cell communication in the nervous and endocrine systems. Production of active neuropeptides requires proteolytic processing of proneuropeptide precursors in secretory vesicles that produce, store, and release neuropeptides that r ...

Prokaryotic subtilisins and eukaryotic proprotein convertases (PCs) are two homologous protease subfamilies that belong to the larger ubiquitous super-family called subtilases. Members of the subtilase super-family are produced as zymogens wherein their propeptide dom ...

The proprotein convertases (PCs) are secretory mammalian serine proteinases related to bacterial subtilisin-like enzymes. The family of PCs comprises nine members, PC1/3, PC2, furin, PC4, PC5/6, PACE4, PC7, SKI-1/S1P, and PCSK9 (Fig. 3.1). While the first seven PCs cleave after single or paired ...

When I became a physician and an endocrinologist in the early 1960s, peptide hormone sequencing was still in its infancy; it was also far removed from my immediate interests. Through chance encounters with prominent teachers and mentors, I later became increasingly convinced that elucida ...

Studies of the biosynthesis of insulin in a human insulinoma beginning in 1965 provided the first evidence for a precursor of insulin, the first such prohormone to be identified. Further studies with isolated rat islets then confirmed that the precursor became labeled more rapidly than insu ...

Aptamers developed for applications in cancer therapy can improve the efficacy of drug treatment and enhance molecular imaging. Aptamers for these purposes are generated from SELEX (Systematic Evolution of Ligands by EXponential enrichment), more precisely cell-based SELEX, a p ...

It is very clear that RNA interference (RNAi) is a potent and versatile tool for gene silencing. One of the hurdles to making siRNA/miRNA a human therapeutic includes effective in vivo delivery and being able to deliver drugs to target cells only. The commercial success of in vivo applications of RNAi h ...

The tissue-specific delivery nanoparticle consists of an antisense oligomer, a cell-penetrating peptide, and an antitumor antibody, each biotinylated and each linked via streptavidin. Within the nanoparticle, the antibody provides specific targeted delivery and binding to ...