A kinetic method for detecting intramolecular peptide H-bonds

2021 ◽  
Author(s):  
Erode N Prabhakaran ◽  
Damodara N Reddy ◽  
Shreya Banerjee

The current method for detection of peptide hydrogen bond (PHB) formation places charge donors/acceptors (D/A) at N-/C-termini of the peptides involved in the putative PHB. The efficiency of the charge...

2007 ◽  
Vol 1062 ◽  
Author(s):  
Sinan Keten ◽  
Markus J. Buehler

ABSTRACTExperimental and computational studies on mechanical unfolding of proteins suggest that rupture forces approach a limiting value of a few hundred pN at vanishing pulling velocities. We develop a fracture mechanics based theoretical framework that considers the free energy competition between entropic elasticity of polypeptide chains and rupture of peptide hydrogen bonds, which we use here to provide an explanation for the intrinsic strength limit of proteins. Our analysis predicts that individual protein domains stabilized by hydrogen bonds can not exhibit rupture forces larger than approximately ≈200 pN, regardless of the presence of a large number of hydrogen bonds. This result explains a wide range of experimental and computational observations.


1983 ◽  
Vol 48 (11) ◽  
pp. 3214-3222 ◽  
Author(s):  
Milan Remko ◽  
Ivan Sekerka ◽  
Vladimír Frecer

The PCILO quantum-chemical method with geometry optimization has been used to study rotation barriers of methyl groups in N-methylacetamide and N,N-dimethylacetamide. In all the cases studied, the eclipsed conformation have been found to be the most stable. Cis form of N-methylacetamide is less stable than the corresponding trans form by 2.0 kJ mol-1. Moreover, the PCILO method has been used to study linear n-mers (n = 4) of N-methylacetamide. On going from the dimer to tri- and tetramers, the hydrogen-bond energies have been found non-additive, and positive cooperativity has been observed. Finally, hydrogen-bond complexes have been studied which were formed by C=O groups of N-methylacetamide and N,N-dimethylacetamide with water, methanol or phenol as proton-donors. The said proton-donors have been found to act as breakers of inter-peptide hydrogen bonds N-H...O=C. The hydrogen bonds formed by methanol are somewhat stronger than those formed by water. In accordance with experiment, the strongest hydrogen bonds with the studied proton-acceptors are formed by phenol.


2019 ◽  
Vol 4 (5) ◽  
pp. 936-946
Author(s):  
Dawn Konrad-Martin ◽  
Neela Swanson ◽  
Angela Garinis

Purpose Improved medical care leading to increased survivorship among patients with cancer and infectious diseases has created a need for ototoxicity monitoring programs nationwide. The goal of this report is to promote effective and standardized coding and 3rd-party payer billing practices for the audiological management of symptomatic ototoxicity. Method The approach was to compile the relevant International Classification of Diseases, 10th Revision (ICD-10-CM) codes and Current Procedural Terminology (CPT; American Medical Association) codes and explain their use for obtaining reimbursement from Medicare, Medicaid, and private insurance. Results Each claim submitted to a payer for reimbursement of ototoxicity monitoring must include both ICD-10-CM codes to report the patient's diagnosis and CPT codes to report the services provided by the audiologist. Results address the general 3rd-party payer guidelines for ototoxicity monitoring and ICD-10-CM and CPT coding principles and provide illustrative examples. There is no “stand-alone” CPT code for high-frequency audiometry, an important test for ototoxicity monitoring. The current method of adding a –22 modifier to a standard audiometry code and then submitting a letter rationalizing why the test was done has inconsistent outcomes and is time intensive for the clinician. Similarly, some clinicians report difficulty getting reimbursed for detailed otoacoustic emissions testing in the context of ototoxicity monitoring. Conclusions Ethical practice, not reimbursement, must guide clinical practice. However, appropriate billing and coding resulting in 3rd-party reimbursement for audiology services rendered is critical for maintaining an effective ototoxicity monitoring program. Many 3rd-party payers reimburse for these services. For any CPT code, payment patterns vary widely within and across 3rd-party payers. Standardizing coding and billing practices as well as advocacy including letters from audiology national organizations may be necessary to help resolve these issues of coding and coverage in order to support best practice recommendations for ototoxicity monitoring.


1969 ◽  
Vol 21 (01) ◽  
pp. 134-143 ◽  
Author(s):  
W. D Walls ◽  
M. S Losowsky

SummaryA kinetic method for the quantitative estimation of plasma F.S.F. activity is described and discussed.This method was applied to normal subjects and to patients with chronic liver disease. The plasma F.S.F. activity was uninfluenced by either sex or age, and the normal range has been defined.A significant decrease in plasma F.S.F. activity was observed in patients with chronic liver disease. Subnormal levels of activity were found in 25% of such patients but were unrelated to episodes of abnormal haemorrhage. Plasma F.S.F. activity tended to be lower in patients with disease of greater clinical severity. In 2 patients showing clinical improvement there was an increase in plasma F. S. F. activity.It was confirmed that plasma fibrinogen levels increase with age.


2017 ◽  
Vol 4 (1) ◽  
pp. 12
Author(s):  
Dessy Lutfiasari ◽  
Mahmudah Mahmudah

The use of the current method of learning very big influence on the growth and development of students' creativity and interest for all subjects to be taught, especially in the use of partograf. From interviews to the 10 students of IV semester Prodi Midwifery (D-III) Kadiri University is known that 4 (40%) of students said it was understood, 4 (40%) of other students say they are confused and 2 (20%) of them said that he was a student not familiar with partograf. This shows the lack of understanding of students in filling partograph. The research objective is to determine the effectiveness of the use of learning methods for skills training simulation with filling partograph the second semester students in Midwifery (D-III) Kadiri University Faculty of Health Sciences in 2015. The research design used is pre experiment with design Static Group Comparison/Posttest Only Control Group Design. The population studied were all students of the second semester in Midwifery (D-III) Faculty of Health Sciences University of Kadiri numbered 50 students and sampling techniques Federer totaled 32 students. This is a research instrument partograph sheet. Results of the study were analyzed using the Mann Whitney test with a significance level of 0.05 were used.The results showed 7 respondents (46.7%) are adept at using partograf with simulation teaching methods and 6 respondents (40.0%) are adept at using partograph with practice learning methods. Data were analyzed by Mann Whitney test obtained ρ = 0.965; α = 0.05 means that H0 is accepted and H1 rejected. This means there is no difference in the effective use of learning methods for skills training simulation with partograph filling. Based on the results of this study are expected to choose the method of learning as a learning method in charging partograph because both methods equally effective.; Keywords: simulation methods, drilling methods, partograph filling


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