PubMed Health⌕ Search

Biomedical subjects

Takafumi Ohyama

Publications and source records attributed to Takafumi Ohyama.

2 recordsLinked to original sources

A novel peptide microarray for protein detection and analysis utilizing a dry peptide array system.

A novel dry peptide microarray system has been constructed that affords a practical solution for protein detection and analysis. This system is an array preparation and assay procedure under dry conditions that uses designed peptides as non-immobilized capture agents for the detection of proteins. The system has several advantages that include its portability and ease-of-use, as well as the fact that vaporization of sample solutions need not be considered. In this study, various proteins have been characterized with an alpha-helical peptide mini-library. When proteins were added to the peptide library array, the fluorescent peptides showed different fluorescent intensities depending on their sequences. The patterns of these responses could be regarded as 'protein fingerprints' (PFPs), which are sufficient to establish the identities of the target proteins. Furthermore, statistical analysis of the resulting PFPs was performed using cluster analysis. The PFPs of the proteins were clustered successfully depending on their families and binding properties. Additionally, the target protein was characterized using a nanolitre system and could be detected down to 1.2 fmol. These studies imply that the dry peptide array system is a promising tool for detecting and analyzing target proteins. The dry peptide array will play a role in development of high-throughput protein-detecting nano/micro arrays for proteomics and ligand screening studies.

Amino Acid Sequence↗

Addition of a peptide fragment on an alpha-helical depsipeptide induces alpha/3(10)-conjugated helix: synthesis, crystal structure, and CD spectra of Boc-Leu-Leu-Ala-(Leu-Leu-Lac)3-Leu-Leu-OEt.

The depsipeptide Boc(1)-Leu(2)-Leu(3)-Ala(4)-Leu(5)-Leu(6)-Lac(7)-Leu(8)-Leu(9)-Lac(10)-Leu(11)-Leu(12)-Lac(13)-Leu(14)-Leu(15)-OEt(16) (1) (Boc = tert-butyloxycarbonyl, Lac = L-lactic acid residue) has been synthesized from the peptide Boc-Leu-Leu-Ala-OEt (2) and a depsipeptide, Boc-(Leu-Leu-Lac)(3)-Leu-Leu-OEt (3). Single crystals of 1 were successfully obtained and the structure has been solved by direct methods (such as Sir2002 and Shake-and-Bake). Interestingly, 1 adopts an alpha/3(10)-conjugated helix containing a kink at the junction of peptide and depsipeptide segments, Leu3-Lac7. This is significantly different from the conformation of 3, which has a straight alpha-helical structure with standard phi and psi angles. Microcrystalline CD spectra were also studied to compare structural properties of 1 and 3. The differences between alpha/3(10)- and alpha-helices appear in these CD spectra.

Circular Dichroism↗