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A Seidel

Publications and source records attributed to A Seidel.

At least 217 records · Page 12Linked to original sources

Orientation, structure, wet-spinning, and molecular basis for supercontraction of spider dragline silk.

This manuscript reviews work from our laboratory that addresses the orientation, secondary structure, wet-spinning, and molecular basis for supercontraction of spider silk. It identifies the poly(alanine) runs as the crystalline regions, establishes the degree of orientation of these regions, and identifies the secondary structural elements of the conserved L-G-X-Q (X = G, S, or N) regions. It also describes methods for spinning very small amounts of protein polymers and it sets forth several molecular-level hypotheses concerning supercontraction.

Amino Acid Sequence↗

Critical parameters for adduct formation of the carcinogen (+)-anti-benzo[a]pyrene-7,8-dihydrodiol 9,10-epoxide with oligonucleotides.

Various parameters relevant for the formation of dG adducts produced in the reaction of individual benzo[a]pyrene diol epoxide (BPDE) stereoisomers with oligonucleotides have been studied. Reaction time, temperature, pH, molar ratio of diol epoxide and oligonucleotide, base sequence, and buffer system were shown to affect the amount of (+)-anti-BPDE dG adducts formed. Optimum experimental conditions for dG adduct formation were different depending on the base sequence context of the oligonucleotide employed [5'-d(CCTATAGATATCC) or 5'-d(CCTATTGCTATCC)]. In general, low temperature to allow a longer reaction time, slightly alkaline Tris-HCl (pH 7.5-8.0) or alkaline phosphate buffer (pH 11), low concentration of organic solvent, and a molar excess of (+)-anti-BPDE promote dG adduct formation with an oligonucleotide. Low incubation temperature and Tris-HCl buffer also favor dG adduct formation of (-)-anti-BPDE and both enantiomers of syn-BPDE to both 5'-d(CCTATAGATATCC) and 5'-d(CCTATTGCTATCC).

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗