. Biological structure and function; proceedings. Biochemistry; Cytology. 286 H. CHANTRENNE was added to the bacterial extracts in certain experiments; this did not change the resuhs appreciably. These results suggest that the protein moiety of catalase made during the restoration period was abnormal, although the enzyme was active. Considerable change in the protein moiety of catalase can probably be brought about without changing much the catalytic properties of the haem; to the contrary, the active centre of penicillinase must be a region of the polypeptide, the catalytic properties of whic
. Biological structure and function; proceedings. Biochemistry; Cytology. 286 H. CHANTRENNE was added to the bacterial extracts in certain experiments; this did not change the resuhs appreciably. These results suggest that the protein moiety of catalase made during the restoration period was abnormal, although the enzyme was active. Considerable change in the protein moiety of catalase can probably be brought about without changing much the catalytic properties of the haem; to the contrary, the active centre of penicillinase must be a region of the polypeptide, the catalytic properties of which are directly affected by. Fig. 3. Changes in catalase properties. Extracts were prepared by sonication from normal bacteria (•) and from bacteria which had been incubated with azagua- nine for 45 min. before adding guanosine. These bacteria were collected i2omin. after the addition of guanosine (O)- The catalase activity of the extracts was determined according to von Euler and Josephson [21] at four different tem- peratures: o", 15", 30 and 45". In the second experiment, an excess bovine serum albumin was added to both extracts. The results are expressed as per cent of the activity measured at o". malformations of the chain. This may account for the greater sensitivity of penicillinase to the damages caused by azaguanine. Our results suggest that 8-azaguanine, like 2-thiouracil and 5- fluorouracil, can affect the structure of the proteins produced by the bacteria which have incorporated the analogue into their nucleic acids. On the other hand, azaguanine exerts a general inhibition of protein synthesis, most probably by disturbing the normal interactions between some soluble and ribosomal ribonucleic acids. References Mandel, H. G.,J. biol. Chetn. 225, 137 (1957). Chantrenne, H., Rec. Trav. chim. Pays-Bas 77, 586 (1958). Chantrenne, H., and Devreux, S., Exp. Cell Res. Suppl. 6, 152 (1958). Chantrenne, H., and Devreux, S., Nature, Lond. 181, 1737 (1958).
Size: 1663px × 1502px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiver, booksubjectbiochemistry
