"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.

    2/45
    but without the dye, they would have grown as ribonuclease II. The no. VI crystals which grew were colored a deep blue, which seems to the eye rather a different color from a dilute solution of the dye. It was found that both the old forro ( no. II 5 and the new fora ( X no. VI ) would grow fro» the solution, sometimes in the same tube. It is. possible that no. II. crystals* are less deeply dyed than no. VI crystals, but this observation needs to be confirmed, f At one time it was^ñiat the two types could be distinguished from their habit and; general appearence, but this has turned KeXidlí- out on occasions to be misleading. The only easily distinguishable o n tica L jar o ne * IjtfíT is the high pleochroism of the no. VI form. The amount of dye in the crystal has been measured \y Mrs. Myra Adelman (unpublished) who finds that the molar ratio of dye to jCpoteln is very approximately : 1 So far it has not proved possible to obtain ribonuclease VI without dye, or with a different dye. Habit and optical properties The typical habit of the new crystals is shown in Figure 2 (a). That of the more usual no. II is shown in Figure 2(b) for comparison. The no. VI crystals are usually asymmetrical rods, 4 % ^ * Ifc^KeT the dimensions in the , b, c and 4 directions being typically ¡J: %. : h ¿2 U¿«fer ]>»( a * íuJL h¿U> y» 4 f of'fe 1**5 Viewed ¿roughly parallel to the..short-est-d^Bensrion .¿they show a high degree of pleochrolsm, the strong absorbtion being when the electric vector is parallel to b . The maximum pleochroic WS» vinciti u ratio fudged b-y-eye to.about 10 to 1, -oeeured^-when* the light
    digitised image 1
    digitised image 2
    digitised image 3