202 FREDERICK G. E. PAUTARD 



states) of proteins although only the a-cross-/? transformation has been 

 proposed as a basis for the change in length of the k-m-e-f proteins dur- 

 ing supercontraction. The evidence for this change is based on the 

 disappearance of the «-arc and the appearance of the cross-/? arc in the 

 diffraction diagrams (Rudall, 1946, 1952). The infrared evidence, on 

 the other hand, emphasizes the crystallographic evidence that, as far 

 as the appearance of the cross-/? form in "mixed" systems is concerned, 

 a contribution is likely to be made by globular proteins. Indeed, in 

 muscle and bacterial flagella, the cross-/? state which is found naturally 

 or produced artificially is just as likely to have been contributed by the 

 actin-like portion as by the myosin-like portion. On the other hand, the 

 disappearance of the a-photograph in the diffraction diagram must be 

 accounted for if any alternative explanation for the molecular changes 

 during supercontraction is to be put forward. Some experiments on 

 the a-keratoses extracted from oxidized wool and hair tend to suggest 

 that for some reason, stable a-proteins can be quantitatively recovered 

 from mixed systems where only the /? or cross-/? configuration can be 

 detected in the x-ray diffraction diagram (Pautard, unpublished re- 

 sults; see also Pautard and Speakman, 1960). In muscle proteins, where 

 the actin component more readily gives the cross-/? diffraction pattern, 

 the actual change in length has been associated with the fibrous myosin 

 component. The evidence for changes in length of actin will be re- 

 ferred to later. 



PREPARATION AND PROPERTIES OF CONTRACTILE PROTEINS 

 FROM FLAGELLA 



Engelhardt (1946) designated sperm ATPase as "spermosin" and 

 suggested that the contractile protein in the flagellum might be some 

 form of myosin. More direct evidence of the role of ATP in the move- 

 ment of sperm "models" has been put forward by Hoffmann-Berling 

 (1955) and by Bishop and Hoffmann-Berling (1959), who have drawn 

 attention to the analogies between the extracted "model" systems and 

 the glycerized myofibril. On the other hand, there is no clear evidence 

 of the relationship between the flagellar proteins and those from mus- 

 cle. Burnasheva (1958) failed to extract actin from bull sperm tails but 

 reported the separation of a myosin-like protein from the same source. 

 In contrast, Child (1959) considered the flagellar protein to be actin- 



