ISSN:
1573-5028
Keywords:
Nicotiana tabacum cv. Samsun NN
;
tobacco mosaic virus
;
PR proteins
;
purification
;
serology
;
thaumatin-like proteins
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The purification to homogeneity of pathogenesis-related (PR) proteins R and S from Nicotiana tabacum cv. Samsun NN leaves has been achieved by using a combination of conventional and high-performance chromatographic supports. The same procedure allowed the purification and the characterization of four other proteins which displayed some properties characteristic of tobacco PR proteins and were shown to accumulate in tobacco leaves in response to virus infection. They can be, therefore, considered as new tobacco PR proteins which we designate as PR-s1,-s2,-r1 and-r2. The relative electrophoretic mobilities (Rf) under non-denaturing conditions were estimated to 0.30 for PR-r1 and-r2, 0.25 for Pr-R, 0.20 for PR-s1 and-s2 and 0.15 for PR-S. On SDS gels PR proteins R and S possessed the same apparent molecular weight (M r 24000) as did PR-proteins s1 and r1 (M r 14500) and PR-s2 and-r2 (M r 13000). However, proteins s1, s2, r1 and r2 had identical electrophoretic mobilities on SDS gels when the loading sample buffer contained no reducing agent. Polyclonal antisera were raised against PR proteins R and S and used in immunoblotting experiments. Proteins R and S were shown to be serologically closely related. No cross-reaction was detected with any of the four new tobacco PR proteins r1, r2, s1 and s2 or with the previously described PR proteins, i.e. PR-1a,-1b,-1c,-2,-N,-O,-P and-Q.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00028774
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