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Type: Package
Title: Prediction of Amyloid Proteins
Version: 1.1
LazyData: TRUE
Date: 2017-10-11
Description: Predicts amyloid proteins using random forests trained on the n-gram encoded peptides. The implemented algorithm can be accessed from both the command line and shiny-based GUI.
License: GPL-3
URL: https://github.com/michbur/AmyloGram
BugReports: https://github.com/michbur/AmyloGram/issues
RoxygenNote: 6.0.1
Depends: R (≥ 3.0.0)
Imports: biogram, ranger, seqinr, shiny
Repository: CRAN
NeedsCompilation: no
Packaged: 2017-10-11 14:35:25 UTC; michal
Author: Michal Burdukiewicz [cre, aut], Piotr Sobczyk [ctb], Stefan Roediger [ctb]
Maintainer: Michal Burdukiewicz <michalburdukiewicz@gmail.com>
Date/Publication: 2017-10-11 14:46:15 UTC

Prediction of amyloids

Description

Amyloids are proteins associated with the number of clinical disorders (e.g., Alzheimer's, Creutzfeldt-Jakob's and Huntington's diseases). Despite their diversity, all amyloid proteins can undergo aggregation initiated by 6- to 15-residue segments called hot spots. Henceforth, amyloids form unique, zipper-like beta-structures, which are often harmful. To find the patterns defining the hot spots, we developed our novel predictor of amyloidogenicity AmyloGram, based on random forests.

Details

AmyloGram is available as R function (predict.ag_model) or shiny GUI (AmyloGram_gui).

The package is enriched with the benchmark data set pep424.

Author(s)

Maintainer: Michal Burdukiewicz <michalburdukiewicz@gmail.com>

References

Burdukiewicz MJ, Sobczyk P, Roediger S, Duda-Madej A, Mackiewicz P, Kotulska M. (2017) Amyloidogenic motifs revealed by n-gram analysis. Scientific Reports 7 https://doi.org/10.1038/s41598-017-13210-9


AmyloGram Graphical User Interface

Description

Launches graphical user interface that predicts presence of amyloids.

Usage

AmyloGram_gui()

Warning

Any ad-blocking software may cause malfunctions.


Random forest model of amyloid proteins

Description

Random forest grown using the ranger package with additional information.

Format

A list of length three: random forest, a vector of important n-grams and the best-performing encoding.

See Also

ranger


Protein test

Description

Checks if an object is a protein (contains letters from one-letter amino acid code).

Usage

is_protein(object)

Arguments

object

character vector where each elemenents represent one amino acid.

Value

TRUE or FALSE.


pep424 data set

Description

Benchmark dataset for PASTA 2.0. 5 sequences shorter than 6 amino acids (1% of the original dataset) were removed.

Usage

pep424

Format

a list of 424 peptides (class SeqFastaAA).

Source

Walsh, I., Seno, F., Tosatto, S.C.E., and Trovato, A. (2014). PASTA 2.0: an improved server for protein aggregation prediction. Nucleic Acids Research gku399.


Predict amyloids

Description

Recognizes amyloids using AmyloGram algorithm.

Usage

## S3 method for class 'ag_model'
predict(object, newdata, ...)

Arguments

object

ag_model object.

newdata

list of sequences (for example as given by read.fasta).

...

further arguments passed to or from other methods.

Examples

data(AmyloGram_model)
data(pep424)
predict(AmyloGram_model, pep424[17])

Print AmyloGram object

Description

Prints ag_model objects.

Usage

## S3 method for class 'ag_model'
print(x, ...)

Arguments

x

ag_model object.

...

further arguments passed to or from other methods.

Examples

data(AmyloGram_model)
print(AmyloGram_model)

Read sequences from .txt file

Description

Read sequence data saved in text file.

Usage

read_txt(connection)

Arguments

connection

a connection to the text (.txt) file.

Details

The input file should contain one or more amino acid sequences separated by empty line(s).

Value

a list of sequences. Each element has class SeqFastaAA. If connection contains no characters, function prompts warning and returns NULL.


Specificity/sensitivity balance

Description

Sensitivity, specificity and Matthew's Correlation Coefficient of AmyloGram for different cutoffs computed on pep424 dataset.

Usage

spec_sens

Format

a data frame with four columns and 99 rows.

Source

Walsh, I., Seno, F., Tosatto, S.C.E., and Trovato, A. (2014). PASTA 2.0: an improved server for protein aggregation prediction. Nucleic Acids Research gku399.

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.