To Compute the Theoretical Isoelectric Point
要计算理论等电点
译者:生物统计家园网 机器人LoveR
描述----------Description----------
This function calculates the theoretical isoelectric point of a protein. Isoelectric point is the pH at which the protein has a neutral charge. This estimate does not account for the post-translational modifications.
此函数计算理论的一种蛋白质的等电点。等电点的pH值是在其中的蛋白质具有中性电荷。这一估计没有考虑到翻译后修饰。
用法----------Usage----------
computePI(seq)
参数----------Arguments----------
参数:seq
Protein sequence as a vector of single chars in upper case
作为向量的单字符大写的蛋白质序列
值----------Value----------
The theoretical isoelectric point (pI) as a numerical vector of length one.
的理论等电点(pI)为长度为1的数值矢量。
注意----------Note----------
Protein pI is calculated using pK values of amino acids described in Bjellqvist et al. See also SEQINR.UTIL for more details.
蛋白质的等电点计算PK值描述的氨基酸在Bjellqvist等。 SEQINR.UTIL更多的细节。
(作者)----------Author(s)----------
D. Charif and J.R. Lobry
参考文献----------References----------
http://www.expasy.org/tools/pi_tool-doc.html but with many trials in case of convergence failure of the non-linear regression procedure. <code>citation("seqinr")</code>
参见----------See Also----------
SEQINR.UTIL
SEQINR.UTIL
实例----------Examples----------
#[]
# Simple sanity check with all 20 amino-acids in one-letter code alphabetical order:[简单的例行性检查与所有20个氨基酸的单字母代码按字母顺序排列:]
#[]
prot <- s2c("ACDEFGHIKLMNPQRSTVWY")
stopifnot(all.equal(computePI(prot), 6.78454))
#[]
# Read a protein sequence in a FASTA file and then compute its pI :[阅读一个FASTA文件中的蛋白质序列,然后计算其等电点:]
#[]
myProts <- read.fasta(file = system.file("sequences/seqAA.fasta", package = "seqinr"), seqtype = "AA")
computePI(myProts[[1]]) # Should be 8.534902[应该是8.534902]