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Biomedical subjects

C C Chiang

Publications and source records attributed to C C Chiang.

26 records · Page 2Linked to original sources
PubMed1982

Unusual intramolecular hydrogen bonding in cycloamanide A, cyclic (LPro-LVal-LPhe-LPhe-LAla-Gly). A crystal structure analysis.

The naturally occurring cyclic hexapeptide, cycloamanide A, has only one intramolecular hydrogen bond. It is a 4 leads to 1 type that encompasses the L Phe-L Ala sequence in which the experimentally determined phi, psi values are +54 degrees, -118 degrees and -88 degrees, -4 degrees, respectively. Even though the chirality is L, L, the phi, psi values are characteristic for a D, L beta-bend, Type II'. The conformation of the molecule was established by a crystal structure determination using X-ray diffraction analysis. Cycloamanide A (C33H42N6O6 . 4H2O) crystallizes in space group P2(1)2(1)2(1) with cell parameters a = 13.307(2) A, b = 24.820(4)A and c = 11.231(1)A.

Hydrogen Bonding↗
PubMedDate not supplied

Cloning and characterization of a disease resistance response gene in pea inducible by Fusarium solani.

Disease resistance response genes (DRRG) of peas are expressed as the tissue is expressing race-specific or nonhost resistance. A pea genomic clone DRRG49-c encompassing one DRRG structural gene, the expression of which is correlated with the expression of disease resistance, was sequenced and characterized. The 2.3-kb genomic segment sequenced encompassed 986 bp 5' to the major transcriptional initiation site, a 474-bp open-reading frame interrupted by one 88-bp AT-rich intron and an additional 574-bp segment 3' from the stop codon. Southern blot analysis indicated that the DRRG structural gene is one of a multigenic family, and an estimated five copies exist within the pea genome. Primer extension analysis of the 5' terminus of the corresponding RNA suggested the presence of one major transcript with possibly two minor transcripts. The major transcript, located 65 bp from the translational initiation site, was expressed when challenged with Fusarium solani f. sp. phaseoli but not with water. The structural gene sequence corresponding to the genomic clone DRRG49-c is not identical with the structural gene of the cDNA clone DRRG49-a used as a probe for northern blot analysis, and thus, a possibility remains that it is not expressed in peas; however, the DRRG49-c promoter was able to express the chloramphenicol acetyltransferase reporter gene in tobacco protoplasts. Western blot analysis using antiserum prepared from a beta-galactosidase-DRRG49-a fusion protein identified the DRRG49 gene product as a major protein accumulating during the host-pathogen interactions.

Amino Acid Sequence↗
PubMedDate not supplied

The Fusarium solani-induced expression of a pea gene family encoding high cysteine content proteins.

Two pea genes, pI39 and pI230, which are specifically induced by two forma specials of Fusarium solani, encode closely related proteins with predicted molecular masses (Mr) of 8.2 and 8 kDa, respectively. Both proteins contain a signal sequence and are cleaved to mature proteins of Mr 5 kDa as indicated by an in vitro translation system. The mature proteins contain about 17% cysteine residues and have the potential to form four disulfide bonds. The two proteins share extensive homology in their signal sequences but much less homology as mature proteins. The cysteine residues of the mature proteins are highly conserved, suggesting functional importance. Southern hybridization suggests these genes belong to a multigene family. The relative accumulations of mRNA levels indicate that the two genes are expressed somewhat differentially. In both the compatible (susceptible) and incompatible reactions between F. solani and pea tissue, pI39 mRNA accumulates more slowly than pI230 mRNA and accumulates to relatively high levels after 24 hr of inoculation. The increase in accumulation of pI230 mRNA occurs within 6 hr and thus correlates with an initial suppression of the growth of both the compatible and incompatible pathogen, which is cytologically observable at 6 hr. pI39 and pI230 belong to a distinct class of pathogenesis-related proteins characterized previously, which are associated with and thus may contribute to nonhost resistance in plants.

Amino Acid Sequence↗
PubMedDate not supplied

The developments of mass urinary screening in Taiwan.

A program of mass urinary screening of elementary and junior high school students has been in operation since August 1990 in Taiwan Province. This program is done once a semester, i.e., twice a year. In the first 3 years, the total number of elementary and junior high school students to be examined in each semester was approx. 2.7 millions. From August 1993, the total number increased to 3.1 millions because the senior high and senior vocational school students were added. The procedures can roughly be divided into five parts: The first part is first urinary screening. The second part is the second urinary screening. The third part is so called the third examination namely serological examination. Life guidance is introduced in the fourth part. The last part is the follow-up system. All the procedures and details will be discussed later.

Glycosuria↗
PubMedDate not supplied

Product development of AG-331 lyophilized powder for injection.

AG-331, a water-soluble glucuronate salt of a potential anticancer drug, was synthesized using a technology described as "Protein Structure-based Drug Design." A lyophilized product containing 44.4% (w/w) of AG-331, 55.6% (w/w) of mannitol and trace of water was developed for parenteral delivery of AG-331. The pre-lyophilized solution, which contains 2.0% (w/v) of AG-331 and 2.5% (w/v) mannitol can be aseptically filtered through commonly used 0.2-micron filters without significant AG-331 loss. The filter of choice was made of PTFE (polytetrafluoroethylene) membrane. The lyophilized product is stable under accelerated conditions for at least 6 months. The product can be sterilized with gamma-irradiation. The AG-331 reconstituted solution in 5% Dextrose Injection, USP is stable in PVC infusion bags for at least 2 days at 5 degrees C and 30 degrees C.

Drug Design↗