Flippen-Anderson, Judith L., Karle, Isabella L.
This Article is from 'Peptides, Chemistry and Biology: Proceedings of the American Peptide Symposium (12th) Held in Cambridge, Massachusetts on 16-21 June 1991', AD-A256 113, p766-767.
Rai, Rajkishor, Vasudev, Prema G, Ananda, Kuppanna, Raghothama, Srinivasarao, Shamala, Narayanaswamy, Karle, Isabella L, ...
The \beta turn segment in designed peptide hairpins has been expanded by the insertion of \beta-, \gamma- and \delta amino acids at the i+2 position. The model octapeptides...
Roy, Rituparna S, Gopi, Hosahudya N, Raghothama, Srinivasa Rao, Karle, Isabella L, Balaram, Padmanabhan
The effects of inserting unsubstituted -amino acids into the strand segments of model -hairpin peptides was investigated by using four synthetic decapeptides,...
Roy, Rituparna S, Gopi, Hosahudya N, Raghothama, S, Gilardi, Richard D, Karle, Isabella L, Balaram, Padmanabhan
The incporation of \beta -amino acid residues into the strand segments of designed \beta -hairpin leads to the formation of polar sheets, since in the case of \beta -peptide strands, all adjacent...
Gudihal, Ravindra, Rappal, Ranganayaki S, Raghothama, Srinivasa, Mandayam, Srinivasan C, Gilardi, Richard D, Karle, Isabella L, ...
Two new cyclohexadepsipeptides have been isolated from the fungus Isaria. Fungal growth in solid media yielded hyphal strands from which peptide fractions were readily isolable by organic-solvent...
Roy, Rituparna S, Karle, Isabella L, Raghothama, S, Balaram, P
Conformational studies on the synthetic 11-aa peptide t-butoxycarbonyl (Boc)-Val-Ala-Phe-$\alpha$-aminoisobutyric acid (Aib)-(R)-$\beta^3$- homovaline ($\beta$Val)-(S)-$\beta^3$-homophenylalanine...
Karle, Isabella L, Gopi, Hosahudya N, Balaram, Padmanabhan
The design of the synthetic 19-residue peptide Boc-Leu-Aib-Val-Ala-Leu5-Aib-Val-D-Ala-D-Leu-Leu10-Val-Phe-Val-Aib-D-Val15-Leu-Phe-Val-Val-OMe (Aib, alpha-aminoisobutyric acid; OMe, methyl ester) was...
Aravinda, Subrayashastry, Shamala, Narayanaswamy, Das, Chittaranjan, Sriranjini, Arumugam, Karle, Isabella L, Balaram, Padmanabhan
Aromatic-aromatic interactions between phenylalanine side chains in peptides have been probed by the structure determination in crystals of three peptides: Boc-Val-Ala-Phe-Aib-Val-Ala-Phe-Aib-OMe, I;...
Hosahudya, Gopi N, Roy, Rituparna S, Raghothama, Srinivasa R, Karle, Isabella L
The incorporation of the -amino acid residues into specific positions in the strands and -turn segments of peptide hairpins is being systematically explored. The presence of an additional torsion...
Karle, Isabella L, Das, Chittaranjan, Balaram, P
The insertion of alpha-hydroxy acids into peptide chains provides a convenient means for investigating the effects of hydrogen bond deletion on polypeptide secondary structures. The crystal...
Karle, Isabella L, Gopi, Hosahudya N, Balaram, Padmanabhan
A beta-hairpin conformation has been characterized in crystals of the decapeptide t-butoxycarbonyl-Leu-Val-betaPhe-Val-DPro-Gly-Leub Phe-Val-Val-methyl ester [bPhe; (S)-b3 homophenylalanine] by x-ray...
Designed beta-Hairpin Peptides with Defined Tight Turn Stereochemistry (2001)
Das, Chittaranjan, Naganagowda, GA, Karle, Isabella L, Balaram, P
The conformational analysis of two synthetic octapeptides, Boc–Leu–Val–Val–D-Pro–L-Ala–Leu–Val–Val–OMe (1) and Boc–Leu–Val–Val–D-Pro–D-Ala–Leu–Val–Val–OMe (2) has...
Karle, Isabella L, Das, Chittaranjan, Balaram, Padmanabhan
The Meccano (or Lego) set approach to synthetic protein design envisages covalent assembly of prefabricated units of peptide secondary structure. Stereochemical control over peptide folding is...
Karle, Isabella L, Perozzo, Mary Ann, Mishra, Vinod K, Balaram, Padmanabhan
Crystals of an ion-channel-forming peptaibol peptide in a partial membrane environment have been obtained by cocrystallizing antiamoebin with n-octanol. The antiamoebin molecule has a bent helical...
Karle, Isabella L, Kaul, Ramesh, Rao, Balaji R, Raghothama, S, Balaram, P
The peptide Boc-Gly-Dpg-Gly-Gly-Dpg-Gly-NHMe (1) has been synthesized to examine the conformational preferences of Dpg residues in the context of a poor helix promoting sequence. Single crystals of 1...
Banerjee, Arindam, Raghothama, Srinivasa Rao, Karle, Isabella L, Balaram, Padmanabhan
The handedness or chirality of molecules, organisms, and elementary particles has been widely appreciated, vindicating Pasteur’s perceptive generalization, “L‘uni-vers est dissymktrique.‿...
A designed beta-hairpin peptide in crystals (1996)
Karle, Isabella L, Awasthi, Satish K, Balaram, Padmanabhan
Beta-hairpin structures have been crystallographically characterized only in very short acyclic peptides, in contrast to helices. The structure of the designed beta-hairpin,...
Karle, Isabella L, Rao, Balaji R, Kaul, Ramesh, Prasad, Sudhanand, Balaram, P
The pept ide Boc- Gly- Dpg- Gly- Val-A la- Leu-A ib- Val-A la- Leu- 0 Me has been designed to examine the structural consequences of placing a short segment with a low helix propensity at the amino...
Solid State and Solution Conformations of a Helical Peptide with a Central Gly-Gly Segment (1996)
Karle, Isabella L, Banerjee, Arindam, Bhattacharjya, Surajit, Balaram, P
The influence of amino acids with contrasting con formational tendencies on the stereochemistry of oligopeptides has been investigated using an octapeptide Boc-Leu-Aib- Val-Gly-Gly-Leu-Aih-Val-OMe,...
Karle, Isabella L, Gurunath, R, Prasad, Sudhanand, Kaul, Ramesh, Rao, Balaji R, Balaram, P
The conformations of three decapeptides containing a helical heptapeptide module attached to a potentially helix destabilizing tripeptide segment have been investigated in single crystals. X-ray...
Karle, Isabella L, Rao, Balaji R, Prasad, Sudhanand, Kaul, Ramesh, Balaram, P
Nonstandard amino acids dipropylglycine (Dpg) and dibutylglycine (Dbg) have been incorporated into penta- to decapeptides in order to impose local restrictions on the polypeptide chain...
Karle, Isabella L, Flippen-Anderson, Judith L, Gurunath, R, Balaram, P
A structural transition from a 310-helix to an alpha-helix has been characterized at high resolution for an octapeptide segment located in 3 different sequences. Three synthetic peptides, decapeptide...
Karle, Isabella L, Flippen-Anderson, Judith L, Agarwalla, S, Balaram, P
The membrane channel-forming polypeptide, Leu '-zervamicin, Ac-Leu-Ile-Gln-ha-Ile5-Thr-Aib-Leu-Aib-Hyp'o-Gln-Aib-Hyp-Aib-Pro'5-Phol ( Aib: a-aminoisobutyric acid; Iva: isovaline; Hyp:...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, K, Balaram, P
The structure of the peptide Boc-Val-Ala-Leu-Aib-Val-Ala-Leu-OMe has been determined in crystals obtained from a dimethylsulfoxide-isopropanol mixture. Crystal parameters are as follows:...
Karle, Isabella L, Flippen-Anderson, Judith L, Sukumar, M, Balaram, P
The packing of peptide helices in crystals of the leucine-rich decapeptide Boc-AibLeu- Aib AibLeu-Leu-Leu- AibLeu-Aib-OMe provides an example of ladder-like leucyl-leucyl interactions between...
Karle, Isabella L, Flippen-Anderson, Judith L, Agarwalla, Sanjay, Balaram, Padmanabhan
Structures in four different crystal forms of [Leu1]zervamicin (zervamicin Z-L, Ac-Leu-Ile-Gln-Iva-Ile5-Thr-Aib-Leu-Aib-Hyp10-Gln-Aib -Hyp-Aib- Pro15-Phol, where Iva is isovaline, Aib is \alpha-amino...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, K, Balaram, P
The isomeric decapeptides Boc-Aib-Ala-Leu-Ala-Aib-Aib-Leu-Ala-Leu-Aib-OMe (II) and Boc- Aib-Ala-Aib- Ala-Leu-Ala-Leu-Aib-Leu- Aib-OMe (III) , are predominantly \alpha-helical with little effect on...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, Kuchibhotla, Balaram, Padmanabhan
The crystal structure of the decapeptide Boc-Aib-Glu(OBzl)-Leu-Aib-Ala-Leu-Aib-Ala-Lys(Z)-Aib-OMe (where Aib is -aminoisobutyryl, Boc is t-butoxycarbonyl, OBzl is benzyl ester, and Z is...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, K, Balaram, P
Three crystalline polymorphs of the helical decapeptide, Boc-Aib-Ala-Leu-Ala-Leu-Aib-Leu-Ala-Leu-Aib-OMe, have been obtained. Antiparallel helix aggregation is observed in crystals grown from...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, K, Balaram, Hemalatha, Balaram, P
The peptide Boc-Val-Val-Aib-Pro-Val-Val-Val-OMe has been synthesized to investigate the effect of introduction of a strong \beta-turn promoting guest segment into an oligopeptide with a tendency to...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, K, Balaram, P
The crystal structures of two helical peptides Boc-Val-Ala-Leu-Aib-Val-Ala-Leu-OMe (VALU-7) and Boc-Val-Ala-Leu-Aib-Val-Ala-Leu-Aib-OMe (VALU-8) have been determined to a resolution of 1.0 and 0.9 A,...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, K, Balaram, P
The incorporation of \alpha-aminoisobutyryl (Aib) residues into peptide sequences facilitates helical folding. Aib-containing sequences have been chosen for the design of rigid helical segments in a...
Karle, Isabella L, Flippen-Anderson, Judith L, Uma, Kuchibhotla, Balaram, Hemalatha, Balaram, Padmanabhan
Two molecules of Boc-Aib-Val-Aib-Aib-Val-Val-Val-Aib-Val-Aib-OMe (where Boc is t-butoxycarbonyl and Aib is \alpha-aminoisobutyryl) cocrystallize in a triclinic cell with different helical...
Karle, Isabella L, Flippen-Anderson, Judith, Uma, Kuchibhotla, Balaram, Padmanabhan
Although the peptide $Boc-{Aib}^1-{Ala}^2-{Leu}^3-{Aib}^4-{Ala}^5-{Leu}^6-{Aib}^7-{Ala}^8-{Leu}^9-{Aib}^{10}-OMe$ [with a t-butoxycarbonyl (Boc) blocking group at the amino terminus, a methyl ester...
Karle, Isabella L, Flippen-Anderson, Judith, Sukumar, Muppalla, Balaram, Padmanabhan
Boc-Trp-Ile-Ala-Aib-Ile-Val-Aib-Leu-Aib-Pro-Ala-Aib-Pro-Aib-Pro-Phe-OMe (where Boc is t-butoxycarbonyl and Aib is \alpha-aminoisobutyric acid), a synthetic apolar analog of the membrane-active fungal...
Karle, Isabella L, Sukumar, Muppalla, Balaram, Padmanabhan
An apolar synthetic analog of the first 10 residues at the ${NH}_2$-terminal end of zervamicin IIA crystallizes in the triclinic space group P1 with cell dimensions a = 10.206 \pm 0.002 A, b = 12.244...
EVALUATION OF THE POTENTIAL BARRIER IN $X_{2}Y_{6}$ MOLECULES (1954)
$^{1}$J. Karle and H. Hauptman. J. Chem. Phys. 18:875 (1950) $^{2}$ J. Karle, J. Chem. Phys. 22:June (1954)
Karle, Isabella L., Das, Chittaranjan, Balaram, Padmanabhan
The Meccano (or Lego) set approach to synthetic protein design envisages covalent assembly of prefabricated units of peptide secondary structure. Stereochemical control over peptide folding is...
Crystal structure of the channel-forming polypeptide antiamoebin in a membrane-mimetic environment
Karle, Isabella L., Perozzo, Mary Ann, Mishra, Vinod K., Balaram, Padmanabhan
Crystals of an ion-channel-forming peptaibol peptide in a partial membrane environment have been obtained by cocrystallizing antiamoebin with n-octanol. The antiamoebin molecule has a bent helical...
Karle, Isabella L., Gopi, Hosahudya N., Balaram, Padmanabhan
A β-hairpin conformation has been characterized in crystals of the decapeptide t-butoxycarbonyl-Leu-Val-βPhe-Val-DPro-Gly-Leu-βPhe-Val-Val-methyl ester [βPhe; (S)-β3 homophenylalanine] by x-ray...
Karle, Jean M., Karle, Isabella L.
The absolute configuration of (−)-mefloquine has been established as 11R,12S by X-ray crystallography of the hydrochloride salt, thus allowing comparison of the configuration of mefloquine's...
Karle, Isabella L., Gopi, Hosahudya N., Balaram, Padmanabhan
The design of the synthetic 19-residue peptide Boc-Leu-Aib-Val-Ala-Leu5-Aib-Val-d-Ala-d-Leu-Leu10-Val-Phe-Val-Aib-d-Val15-Leu-Phe-Val-Val-OMe (Aib, α-aminoisobutyric acid; OMe, methyl ester) was...
Karle, Isabella L., Karle, Jerome
The cyclic hexapeptides (Gly-L-Pro-L-Pro-Gly-L-Pro-L-Pro) in the (peptide—Mg—peptide)2+ complex have nearly identical asymmetric conformations. Each has two cis Pro-Pro linkages and lacks any...
Karle, Isabella L., Yagi, Haruhiko, Sayer, Jane M., Jerina, Donald M.
Benzo[a]pyrene 7,8-diol 9,10-epoxide adducts in DNA are implicated in mutagenesis, and their formation from the diol epoxides and subsequent incorrect replication by human DNA polymerases provide an...
Karle, Isabella L., Karle, Jerome
A Patterson-type map computed with Bijvoet differences squared as coefficients, (ǀFhǀ - ǀF-hǀ)2, as recommended by Rossmann, readily yielded the position of the S atom. The experiment was...
Conformation of uncomplexed natural antamanide crystallized from CH3CN/H2O
Karle, Isabella L., Wieland, T., Schermer, D., Ottenheym, H. C. J.
Natural antamanide, a cyclic decapeptide from Amanita phalloides, has been shown to have the same conformation for the backbone and comparable side groups as the biologically active synthetic [Phe4,...
Configuration of the C(20) Epimer of 7,8-Dihydrobatrachotoxinin A
7,8-Dihydrobatrachotoxinin A is an intermediate in the synthesis of batrachotoxin, the extremely potent venom from the Colombian frog Phyllobates aurotaenia. A crystal structure analysis by x-ray...
Karle, Isabella L., Karle, Jerome, Wieland, Th., Burgermeister, Wolfgang, Faulstich, Heinz, Witkop, Bernhard
Antamanide, a cyclic decapeptide isolated from the poisonous mushroom Amanita phalloides, preferably complexes with Na+, but in less polar solvents, e.g., acetonitrile, also with Li+ or K+. The...
Roy, Rituparna S., Karle, Isabella L., Raghothama, S., Balaram, P.
Conformational studies on the synthetic 11-aa peptide t-butoxycarbonyl (Boc)-Val-Ala-Phe-α-aminoisobutyric acid (Aib)-(R)-β3-homovaline (βVal)-(S)-β3-homophenylalanine...
Roy, Rituparna S., Gopi, Hosahudya N., Raghothama, Srinivasarao, Gilardi, Richard D., Karle, Isabella L, Balaram, Padmanabhan
The incorporation of β-amino acid residues into the strand segments of designed β-hairpin leads to the formation of polar sheets, since in the case of β-peptide strands, all adjacent carbonyl...
Roy, Rituparna S., Gopi, Hosahudya N., Raghothama, Srinivasarao, Karle, Isabella L., Balaram, Padmanabhan
The effects of inserting un-substituted ω-amino acids into the strand segments of model β-hairpin peptides was investigated by using four synthetic decapeptides,...
Karle, Isabella L., Das, Chittaranjan, Balaram, Padmanabhan
The Meccano (or Lego) set approach to synthetic protein design envisages covalent assembly of prefabricated units of peptide secondary structure. Stereochemical control over peptide folding is...
Crystal structure of the channel-forming polypeptide antiamoebin in a membrane-mimetic environment
Karle, Isabella L., Perozzo, Mary Ann, Mishra, Vinod K., Balaram, Padmanabhan
Crystals of an ion-channel-forming peptaibol peptide in a partial membrane environment have been obtained by cocrystallizing antiamoebin with n-octanol. The antiamoebin molecule has a bent helical...
Karle, Isabella L., Gopi, Hosahudya N., Balaram, Padmanabhan
A β-hairpin conformation has been characterized in crystals of the decapeptide t-butoxycarbonyl-Leu-Val-βPhe-Val-DPro-Gly-Leu-βPhe-Val-Val-methyl ester [βPhe; (S)-β3 homophenylalanine] by x-ray...
Karle, Jean M., Karle, Isabella L.
The absolute configuration of (−)-mefloquine has been established as 11R,12S by X-ray crystallography of the hydrochloride salt, thus allowing comparison of the configuration of mefloquine's...
Karle, Isabella L., Gopi, Hosahudya N., Balaram, Padmanabhan
The design of the synthetic 19-residue peptide Boc-Leu-Aib-Val-Ala-Leu5-Aib-Val-d-Ala-d-Leu-Leu10-Val-Phe-Val-Aib-d-Val15-Leu-Phe-Val-Val-OMe (Aib, α-aminoisobutyric acid; OMe, methyl ester) was...
Karle, Isabella L., Karle, Jerome
The cyclic hexapeptides (Gly-L-Pro-L-Pro-Gly-L-Pro-L-Pro) in the (peptide—Mg—peptide)2+ complex have nearly identical asymmetric conformations. Each has two cis Pro-Pro linkages and lacks any...
Karle, Isabella L., Yagi, Haruhiko, Sayer, Jane M., Jerina, Donald M.
Benzo[a]pyrene 7,8-diol 9,10-epoxide adducts in DNA are implicated in mutagenesis, and their formation from the diol epoxides and subsequent incorrect replication by human DNA polymerases provide an...
Karle, Isabella L., Karle, Jerome
A Patterson-type map computed with Bijvoet differences squared as coefficients, (ǀFhǀ - ǀF-hǀ)2, as recommended by Rossmann, readily yielded the position of the S atom. The experiment was...
Conformation of uncomplexed natural antamanide crystallized from CH3CN/H2O
Karle, Isabella L., Wieland, T., Schermer, D., Ottenheym, H. C. J.
Natural antamanide, a cyclic decapeptide from Amanita phalloides, has been shown to have the same conformation for the backbone and comparable side groups as the biologically active synthetic [Phe4,...
Configuration of the C(20) Epimer of 7,8-Dihydrobatrachotoxinin A
7,8-Dihydrobatrachotoxinin A is an intermediate in the synthesis of batrachotoxin, the extremely potent venom from the Colombian frog Phyllobates aurotaenia. A crystal structure analysis by x-ray...
Karle, Isabella L., Karle, Jerome, Wieland, Th., Burgermeister, Wolfgang, Faulstich, Heinz, Witkop, Bernhard
Antamanide, a cyclic decapeptide isolated from the poisonous mushroom Amanita phalloides, preferably complexes with Na+, but in less polar solvents, e.g., acetonitrile, also with Li+ or K+. The...
Roy, Rituparna S., Karle, Isabella L., Raghothama, S., Balaram, P.
Conformational studies on the synthetic 11-aa peptide t-butoxycarbonyl (Boc)-Val-Ala-Phe-α-aminoisobutyric acid (Aib)-(R)-β3-homovaline (βVal)-(S)-β3-homophenylalanine...