"A new crystal form of ribonuclease"

Date:: [1955]

Reference:: PP/CRI/H/1/35

Catalogue details

Licence: In copyright

Credit: "A new crystal form of ribonuclease". Source: Wellcome Collection.

1/45

fi fan * 'i Zahtu r. i Introduction In order to attach a heavy atom to the ribonuclease molecule attempts have been made to grow crystals of the protein in the presence of certain dy^es. In most cases some dye was incorporated in the crystal (usually ribonuclease II ) without any change^in the space group, and with only very slight changes in the cell dimensions ('<;*¡ f ~ f,K<uW. ».*«* . ). In toftvfc. « one case, however, the dyed cry^stal? wa® found to be ä we- ht%he*to—w*Hrs covered type, which -he- have called rÄbonuclease VI. Although the space group ( 02 ) was different from that of ribonuclease II ( P2^ ) it soon became clear that the two frjoms were closely related. This note describes briefly our preliminary studues of ribonuclease VI, and discusses the nature of its relationship to ribonuclease II. Method of growth The crystals were grown by Dr. Murray Vernon King as part of his general program to attach a heavy atom to ribonuclease. The general methods used for growing ribonuclease crystals have been described elsewhere( k**$, *'•*'-* , AíUWív-. i » K • ), The protein was Armour bovine ribonuclease. The dye was ( ielopU**l ÇLe. J tatraiodophenolsulphòphthalein its chemical formula is , ... . jfr. feu^uU ¿y*« Z - /M>kù. shown in Figure 1. T he protein co nf nm. 1 Igjior^waa—a.bou4~3^ and the dye was present in a 1:1 molar ratio. The crystals were grown at a pH of about 5 in a solvent having 50% by volume of tertiary butyl alcohol. Under these conditions.