生物化学技术

Successful procedures for the isolation and culture of large-vessel endothelial cells (EC), were first reported in the early seventies (1,2). Since then, microvascular EC have been isolated from various organs, such as adrenal gland (3), brain (4), skin (5), retina (6), and myocardium (7). The init ...

Because of their extensive availability and the wide spectrum of carbohydrates that may be specifically bound, lectins have become essential reagents for detection and quantitation of glycoconjugates in solution and in cell surfaces, identification and separation of cells, and f ...

Soybean agglutinin (SBA) is a plant lectin, a glycoprotein of nonimmune origin that binds specifically to cell surface carbohydrates through noncovalent combinations and thus provokes agglutination of the bound cells. SBA has been used, therefore, to fractionate a variety of cell typ ...

What was thought at the time to be a real breakthrough in myeloma therapy came in 1983 when McElwain reported that complete remission could be gained by means of a single, very high, dose of melphalan (HDM). Between 20 and 30% of patients attain complete remission with HDM (1). These observations led direc ...

The specific binding of lectins to the carbohydrate moieties of glycoproteins and glycohpids on the cell surface has been shown to result in a variety of signal transduction processes (1,2). One of the most dramatic effects of the interaction of lectins with cells is mitogenic stimulation, e.g., ...

When Nowell (1) used a preparation of phytohemagglutinin (PHA) to separate red and white blood cells (a procedure described a decade earlier ), the consequences were far-reaching for studies of both lectins and lymphocytes The key observation was that, in addition to the expected agglutina ...

Resting lymphocytes can be induced to undergo DNA synthesis and subsequently cell division and proliferation by a wide variety of agents, but undoubtedly lectins constitute the most convenient generic group of mitogens to pick off the shelf as reagents. Under the influence of strongly mit ...

Site-selective scission of genomes is quite important for future biotechnology. However, naturally occurring restriction enzymes cut these huge DNAs at too many sites and cannot be used for this purpose. Recently, we have developed a completely chemistry-based artificial restric ...

The biochemical stability and desirable hybridization properties of peptide nucleic acids (PNA) coupled to the robustness of the peptidic chemistry involved in their oligomerization make them an attractive nucleic acid tag to encode molecules and program their assembly into hig ...

Noncoding RNAs are attractive targets for molecular recognition because of the central role they play in gene expression. Since most noncoding RNAs are in a double-helical conformation, recognition of such structures is a formidable problem. Herein, we describe a method for sequence-s ...

The guanine quadruplex is a secondary structure formed by DNA and RNA that has been implicated in regulation of gene expression and maintenance of genome stability. Guanine-rich PNA oligomers can invade DNA or RNA quadruplex targets to form heteroquadruplex structures. Affinities in t ...

Peptide nucleic acids (PNAs) are a class of artificial DNA/RNA analogues that have unique physicochemical properties, which include a high chemical stability, resistance to nucleases and proteases, and higher mismatch sensitivity than DNA. PNAs were initially anticipated to be use ...

Peptide nucleic acids (PNAs) have very attractive properties for applications in nuclear medicine. Because PNAs have high selectivity for DNA/RNA recognition, resistance to nuclease/protease degradation, and high thermal and radiolytic stabilities, PNA bioconjugates co ...

Chiral open-chain PNAs have been shown to have improved properties in terms of control of helical handedness, DNA affinity, sequence selectivity, and cellular uptake. They can be synthesized either using preformed chiral monomers or by means of a submonomeric strategy. The former is prefe ...

Incorporating a cyclopentane ring into the two-carbon unit of a peptide nucleic acid backbone increases its binding affinity to complementary nucleic acid sequences. This approach is a general method to improve binding and can be applied at either purine or pyrimidine bases.

Peptide nucleic acids (PNAs) are attractive, as compared to other classes of oligonucleotides that have been developed to date, in that they are relatively easy to synthesize and modify, hybridize to DNA and RNA with high affinity and sequence selectivity, and are resistant to enzymatic degr ...

Peptide nucleic acids (PNAs) are a class of artificial DNA/RNA analogues that have unique physicochemical properties, which include a high chemical stability, resistance to nucleases and proteases and higher mismatch sensitivity than DNA. PNAs were initially anticipated to be use ...

The ability to directly manipulate the human genome to correct a disease-related mutation, introduce a sequence change that would lead to site-specific gene knockout, or increase gene expression is a very powerful tool with tremendous clinical value. Triplex formation by synthetic DNA ...

Cellular delivery methods are a prerequisite for cellular studies with PNA. This chapter describes PNA cellular delivery using cell-penetrating peptide (CPP)–PNA conjugates and transfection of PNA–ligand conjugates mediated by cationic lipids. Furthermore, two endosomo ...

Reactions templated by a specific nucleic acid sequence have emerged as an attractive strategy for nucleic acid sensing. The Staudinger reaction using an azide-quenched fluorophore and a phosphine is particularly well suited by virtue of its bioorthogonality and biocompatibili ...