• Title/Summary/Keyword: protein structures

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Reviving GOR method in protein secondary structure prediction: Effective usage of evolutionary information

  • Lee, Byung-Chul;Lee, Chang-Jun;Kim, Dong-Sup
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2003.10a
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    • pp.133-138
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    • 2003
  • The prediction of protein secondary structure has been an important bioinformatics tool that is an essential component of the template-based protein tertiary structure prediction process. It has been known that the predicted secondary structure information improves both the fold recognition performance and the alignment accuracy. In this paper, we describe several novel ideas that may improve the prediction accuracy. The main idea is motivated by an observation that the protein's structural information, especially when it is combined with the evolutionary information, significantly improves the accuracy of the predicted tertiary structure. From the non-redundant set of protein structures, we derive the 'potential' parameters for the protein secondary structure prediction that contains the structural information of proteins, by following the procedure similar to the way to derive the directional information table of GOR method. Those potential parameters are combined with the frequency matrices obtained by running PSI-BLAST to construct the feature vectors that are used to train the support vector machines (SVM) to build the secondary structure classifiers. Moreover, the problem of huge model file size, which is one of the known shortcomings of SVM, is partially overcome by reducing the size of training data by filtering out the redundancy not only at the protein level but also at the feature vector level. A preliminary result measured by the average three-state prediction accuracy is encouraging.

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Effects of gamma irradiation on the functional and structural characteristics of soy protein isolates (방사선 조사가 분리대두단백의 기능적, 구조적 특성에 미치는 영향)

  • 오경남;이숙영
    • Korean journal of food and cookery science
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    • v.20 no.3
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    • pp.256-264
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    • 2004
  • The effects of irradiation on the functional and structural characteristics of soy protein isolates were studied. Soymilk was irradiated at 1, 5, and l0kGy, after which soy protein isolates were prepared. The functional properties of soy protein isolates were examined including solubility, emulsion capacity and stability, foam capacity and stability, structural properties as represented by SDS-PAGE pattern, and secondary and tertiary structures. The solubility and emulsion capacity were increased by radiation treatment at 1kGy however the values were adversely affected again as dosage was increased above 5kGy. As irradiation dosage increased, an increase of foaming capacity at 1kGy and a decreasing turnover afterwards were also noted in foaming capacity, although the differences were not statistically significant. The SDS-PAGE pattern showed fragmentation and aggregation of protein molecules as affected by irradiation in proportion to the dosage increase. The results of CD and fluorescence spectroscopy revealed increased aperiodic structure contents with the dosage increase. It was assumed that irradiation dosagefrom 5 to l0kGy could initiate minimal denaturation of protein in various foods compared to general heat treatment.

Comparative Study of Nucletic Acid Binding of the Purified RBF Protein and Its Inhibition of PKR phosphorylation (RBF정제단백질의 핵산결합도 및 PKR효소의 인산화억제효과의 비교에 관한 연구)

  • 박희성;김인수
    • Journal of Life Science
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    • v.8 no.2
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    • pp.119-125
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    • 1998
  • Column-purified double-stranded RNA binding factor (RBF) protein was tested for its binding affinity for the different forms of nucleic acids structure such as single-stranded(ss) and double-stranded(ds)RNA and ss- and dsDNA. The RBF protein was incubated with each of these nucleic acid structures in separate reactions and its comparative binding affnity was visualized by SDS-polyacrylamide gel electrophoresis. The RBF protein bound to the dsRNA molecule to form a tight RNA:protein complex in agreement with previous studies, but not to the other nucleic acid molecules confirming its distinctive affinity for the dsRNA structure. In phosphorylation assay in vito, the purified RBF protein significantly inhibited the autophosphorylation of the PKR derived from not only human but mouse source in the presence of poly(I):poly(C). It is suggesting that PKR vs. RBF is similarly under a competitive interaction among different eukaryotic organisms during protein synthesis.

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Fabrication of Nanopatterns for Biochip by Nanoimprint Lithography (나노임프린트를 이용한 바이오칩용 나노 패턴 제작)

  • Choi, Ho-Gil;Kim, Soon-Joong;Oh, Byung-Ken;Choi, Jeong-Woo
    • KSBB Journal
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    • v.22 no.6
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    • pp.433-437
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    • 2007
  • A constant desire has been to fabricate nanopatterns for biochip and the Ultraviolet-nano imprint lithography (UV-NIL) is promising technology especially compared with thermal type in view of cost effectiveness. By using this method, nano-scale to micro-scale structures also called nanopore structures can be fabricated on large scale gold plate at normal conditions such as room temperature or low pressure which is not possible in thermal type lithography. One of the most important methods in fabricating biochips, immobilizing, was processed successfully by using this technology. That means immobilizing proteins only on the nanopore structures based on gold, not on hardened resin by UV is now possible by utilizing this method. So this selective nano-patterning process of protein can be useful method fabricating nanoscale protein chip.

Characterization of Yeast Protein Hydrolysate for Potential Application as a Feed Additive

  • Ju Hyun Min;Yeon Ju Lee;Hye Jee Kang;Na Rae Moon;Yong Kuk Park;Seon-Tea Joo;Young Hoon Jung
    • Food Science of Animal Resources
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    • v.44 no.3
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    • pp.723-737
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    • 2024
  • Yeast protein can be a nutritionally suitable auxiliary protein source in livestock food. The breakdown of proteins and thereby generating high-quality peptide, typically provides nutritional benefits. Enzyme hydrolysis has been effectively uesed to generate peptides; however, studies on the potential applications of different types of enzymes to produce yeast protein hydrolysates remain limited. This study investigated the effects of endo- (alcalase and neutrase) and exotype (flavourzyme and prozyme 2000P) enzyme treatments on yeast protein. Endotype enzymes facilitate a higher hydrolysis efficiency in yeast proteins than exotype enzymes. The highest degree of hydrolysis was observed for the protein treated with neutrase, which was followed by alcalase, prozyme 2000P, and flavourzyme. Furthermore, endotype enzyme treated proteins exhibited higher solubility than their exotype counterparts. Notably, the more uniform particle size distribution was observed in endotype treated yeast protein. Moreover, compared with the original yeast protein, the enzymatic protein hydrolysates possessed a higher content of β-sheets structures, indicating their higher structural stability. Regardless of enzyme type, enzyme treated protein possessed a higher total free amino acid content including essential amino acids. Therefore, this study provides significant insights into the production of protein hydrolysates as an alternative protein material.

Protein Phosphatase 1D (PPM1D) Structure Prediction Using Homology Modeling

  • Nagarajan, Santhosh Kumar;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.9 no.1
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    • pp.35-40
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    • 2016
  • Protein phosphatase manganese dependent 1D (PPM1D) is one of the Ser/Thr protein phosphatases belongs to the PP2C family. They play an important role in cancer tumorigenesis of various tumors including neuroblastoma, pancreatic adenocarcinoma, medulloblastoma, breast cancer, prostate cancer and ovarian cancer. Even though PPM1D is involved in the pathophysiology of various tumors, the three dimensional protein structure is still unknown. Hence in the present study, homology modelling of PPM1D was performed. 20 different models were modelled using single- and multiple-template based homology modelling and validated using different techniques. Best models were selected based on the validation. Three models were selected and found to have similar structures. The predicted models may be useful as a tool in studying the pathophysiological role of PPM1D.