The Protein Text 81 



Ribonuclease (79) 



*lys-glu-thr-ala-ala-ala-lys-phc-glun-aig ; lys-ser-arg-aspn-leu-lhr-lys-asp-aig ; lys-aspn ; 



tyr-glun-ser-tyr ; tyr-Iys; lys-his; asp-ala-ser-val* 



Salmine(80, 81) 



*pro-arg-arg; arg-pro-val-arg-arg; pro-ileu-arg; val-gly; arg-val-ser-arg ; arg-ileu-arg; 



arg-ala-ser-arg ; arg-gly-gly-arg; arg-ser-ser-arg ; val-gly; 



Serum albumin (37) 



*asp-ala (man); *asp-thr (cattle); 



Silk fibroin (Bombyx) (82, 83, 84) 



gly-ala-gly-ala-gly-[ser-gly-(ala-gly)„]8-ser-gly-ala-ala-gly-tyr 



n usually 2, mean value always 2. 



gly-val-gly; tyr-gly; phe-gly; gly-ser-pro-tyr-pro ; tyr-pro-ser-tyr 



Tobacco mosaic virus (48) 

 thr-ser-gly-pro-ala-thr* 



Tropomyosin (52) 

 ala-ileu-met-thr-ser-ileu"'' 



Trypsinogen (85) 

 *val-asp-asp-asp-asp-lys-ileu 



Vasopressin (40) 

 *cys-tyr-phe-glun-aspn-cys-pro-arg-gly-NH2* 



Wool (86) 



ser-cys; gly-cys; thr-cys; ala-cys; leu-cys; cys-gly; cys-thr; cys-ala; cys-val; cys-leu; 



cys-phe ; 



remains whether any of the blank cells represent forbidden combinations, 

 or whether they are merely the result of accidents of sampling. 



To answer this question statistically, the frequencies of occurrence of various 

 combinations have been plotted in Fig. 2. There are more blank cells here than 

 in Fig. 1, as a portion of the data has been discarded to avoid obvious sources 

 of bias. Thus the sequences of silk, collagen, wool and protamine have been 

 omitted, since these proteins have an obviously aberrant structure. Likewise, 

 sequences of less than three residues have not been used, since the ease of 



