计算蛋白质分子量大小（MW）、等电点（pI）和消光系数，mwpi,# -*- coding

计算蛋白质分子量大小（MW）、等电点（pI）和消光系数，mwpi,# -*- coding

# -*- coding: UTF-8 -*-AA="ACDEFGHIKLMNPQRSTVWY"AA_residue={'A': 71.0788,'C': 103.1388,'D': 115.0886,'E': 129.1155,'F': 147.1766,'G': 57.0519,'H': 137.1411,'I': 113.1594,'K': 128.1741,'L': 113.1594,'M': 131.1926,'N': 114.1038,'P': 97.1167,'Q': 128.1307,'R': 156.1875,'S': 87.0782,'T': 101.1051,'V': 99.1326,'W': 186.2132,'Y': 163.176}pI_e={'C': 9.0,'D': 4.0,'E': 4.5,'H': 6.4,'K': 10.4,'R': 12.0,'Y': 10.0}COOH="CDEY"NH2="HKR"P=raw_input(u"请输入蛋白序列:\n",)number={k:P.count(k) for k in AA}a=0for k in AA:    a += number[k]*AA_residue[k]E=(number['Y']*1490+number['W']*5500+number['C']/2*125)/adef f(x) :    b=0    c=0    for m in COOH:        b += (number[m]*(10**x))/(10**x+10**pI_e[m])    for n in NH2:        c += (number[n]*10**pI_e[n])/(10**x+10**pI_e[n])    return b+10**x/(10**x+10**3.2)-10**8.2/(10**x+10**8.2)-cr=3.2s=12.0x=(r+s)/2for i in range(11) :    if f(x)>0:        s=x        x=(r+s)/2    elif f(x)<0:        r=x        x=(r+s)/2print(u"分子量大小为: "+str(round((a+18.01524)/1000,2))+u" kD    pI值为: "+str(round(x,2)))print(u"消光系数："+str(round(E,2)))