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Amino Acids, Peptides, and Proteins Commons

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Full-Text Articles in Amino Acids, Peptides, and Proteins

Beta-Lysine Discrimination By Lysyl-Trna Synthetase, Marla S. Gilreath, Hervé Roy, Tammy J. Bullwinkle, Assaf Katz, Michael Ibba, William Wiley Navarre Sep 2011

Beta-Lysine Discrimination By Lysyl-Trna Synthetase, Marla S. Gilreath, Hervé Roy, Tammy J. Bullwinkle, Assaf Katz, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P is modified with (R)‐β‐lysine by the lysyl‐tRNA synthetase (LysRS) paralog PoxA. PoxA specificity is orthogonal to LysRS, despite their high similarity. To investigate α‐ and β‐lysine recognition by LysRS and PoxA, amino acid replacements were made in the LysRS active site guided by the PoxA structure. A233S LysRS behaved as wild type with α‐lysine, while the G469A and A233S/G469A variants decreased stable α‐lysyl‐adenylate formation. A233S LysRS recognized β‐lysine better than wildtype, suggesting a role for this residue in discriminating α‐ and β‐amino acids. Both enantiomers of β‐lysine were substrates for tRNA aminoacylation by LysRS, which, together with …


The Trna Synthetase Paralog Poxa Modifies Elongation Factor-P With (R)-Β-Lysine, Hervé Roy, S. Betty Zou, Tammy J. Bullwinkle, Benjamin S. Wolfe, Marla S. Gilreath, Craig J. Forsyth, William Wiley Navarre, Michael Ibba Aug 2011

The Trna Synthetase Paralog Poxa Modifies Elongation Factor-P With (R)-Β-Lysine, Hervé Roy, S. Betty Zou, Tammy J. Bullwinkle, Benjamin S. Wolfe, Marla S. Gilreath, Craig J. Forsyth, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with α-lysine at low efficiency. Cell-free extracts containing non–α-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of β-lysine, a substrate also predicted by genomic analyses. EF-P was efficiently functionally modified with (R)-β-lysine but not (S)-β-lysine or genetically encoded α-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases.


Antivirulence Potential Of Tr-700 And Clindamycin On Clinical Isolates Of Staphylococcus Aureus Producing Phenol-Soluble Modulins, Jason Yamaki, Timothy Synold, Annie Wong-Beringer Jun 2011

Antivirulence Potential Of Tr-700 And Clindamycin On Clinical Isolates Of Staphylococcus Aureus Producing Phenol-Soluble Modulins, Jason Yamaki, Timothy Synold, Annie Wong-Beringer

Pharmacy Faculty Articles and Research

Staphylococcus aureus strains (n = 50) causing complicated skin and skin structure infections produced various levels of phenol-soluble modulin alpha-type (PSMα) peptides; some produced more than twice that produced by the control strain (LAC USA300). TR-700 (oxazolidinone) and clindamycin strongly inhibited PSM production at one-half the MIC but exhibited weak to modest induction at one-fourth and one-eighth the MICs, primarily in low producers. Adequate dosing of these agents is emphasized to minimize the potential for paradoxical induction of virulence.


The Energy Landscape Analysis Of Cancer Mutations In Protein Kinases, Anshuman Dixit, Gennady M. Verkhivker Jan 2011

The Energy Landscape Analysis Of Cancer Mutations In Protein Kinases, Anshuman Dixit, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

The growing interest in quantifying the molecular basis of protein kinase activation and allosteric regulation by cancer mutations has fueled computational studies of allosteric signaling in protein kinases. In the present study, we combined computer simulations and the energy landscape analysis of protein kinases to characterize the interplay between oncogenic mutations and locally frustrated sites as important catalysts of allostetric kinase activation. While structurally rigid kinase core constitutes a minimally frustrated hub of the catalytic domain, locally frustrated residue clusters, whose interaction networks are not energetically optimized, are prone to dynamic modulation and could enable allosteric conformational transitions. The results …


Thiazolyl N-Benzyl-Substituted Acetamide Derivatives: Synthesis, Src Kinase Inhibitory And Anticancer Activities, Asal Fallah-Tafti, Alireza Foroumadi, Rakesh Tiwari, Amir Nasrolahi Shirazi, David G. Hangauer, Yahao Bu, Tahmineh Akbarzadeh, Keykavous Parang, Abbas Shafiee Jan 2011

Thiazolyl N-Benzyl-Substituted Acetamide Derivatives: Synthesis, Src Kinase Inhibitory And Anticancer Activities, Asal Fallah-Tafti, Alireza Foroumadi, Rakesh Tiwari, Amir Nasrolahi Shirazi, David G. Hangauer, Yahao Bu, Tahmineh Akbarzadeh, Keykavous Parang, Abbas Shafiee

Pharmacy Faculty Articles and Research

KX2-391 (KX-01/Kinex Pharmaceuticals), N-benzyl-2-(5-(4-(2-morpholinoethoxy)phenyl)pyridin-2-yl)acetamide, is a highly selective Src substrate binding site inhibitor. To understand better the role of pyridine ring and N-benzylsubstitution in KX2-391 and establish the structure-activity relationship, a number of N-benzyl substituted (2-morpholinoethoxy)phenyl)thiazol-4-yl)acetamide derivatives containing thiazole instead of pyridine were synthesized and evaluated for Src kinase inhibitory activities. The unsubstituted N-benzyl derivative (8a) showed the inhibition of c-Src kinase with GI50 values of 1.34 μM and 2.30 M in NIH3T3/c-Src527F and SYF/c-Src527F cells, respectively. All the synthesized compounds were evaluated for inhibition of cell proliferation of human colon carcinoma (HT-29), breast carcinoma (BT-20), and leukemia (CCRF-CEM) cells. …


Fatty Acyl Amide Dderivatives Of Doxorubicin: Synthesis And In Vitro Anticancer Activities, Bhupender S. Chhikara, Nicole St. Jean, Deendayal Mandal, Anil Kumar, Keykavous Parang Jan 2011

Fatty Acyl Amide Dderivatives Of Doxorubicin: Synthesis And In Vitro Anticancer Activities, Bhupender S. Chhikara, Nicole St. Jean, Deendayal Mandal, Anil Kumar, Keykavous Parang

Pharmacy Faculty Articles and Research

Doxorubicin is an anticancer drug extensively used in anticancer therapy. Doxorubicin is highly hydrophilic, has short half-life, and its use is associated with severe side effects at high doses. Fatty acyl amide derivatives of doxorubicin were synthesized with the expectation to improve the lipophilicity and anticancer activity of the drug. The lipophilicity was enhanced with the increase in chain length of fatty acyl moiety. Conjugation of 4-amino group with fatty acids through an amide bond reduced the anticancer activity in leukemia, breast, ovarian, and colon cancer cell lines, suggesting that the presence of free amino group is required for anticancer …