Four types of scrapie in goats differentiated from each other and bovine spongiform encephalopathy by biochemical methods

Table 2 PrP^res parameters that differentiate TSE-types in goats

PrP^res parameter	CS-1	CS-2	CS-CH1641	BSE	AS
Glycoprofile^a
M%/D% ratio, Sha31	High (> 0.3)	High (> 0.3)	High (> 0.3)	Low (< 0.2)	NA
N%, Sha31	High (> 8%)	High (> 8%)	High (> 8%)	Low (< 8%)	NA
N-terminus level^b
Normal PK: 12B2/Sha31 ratio	High (0.8–1.3)	Interm. (0.3–0.7)	Low (< 0.2)	Low (< 0.2)	NA
High PK: P4/SAF84 ratio	High (1.4-4)	Interm. (0.2–1.3)	ND	ND	NA
High PK: A’/A ratio, SAF34 + Bar224	High (> 0.3)	High (> 0.3)	ND	Low (0.8–1.3)	minute (≪ 0.8)
kDa (N-band)^c
Triplex-WB, Sha31	19.9–21.6	19.3–20.6	18.5–19.5^e	18.5–19.5	NA
ISS-WB, SAF84	17.5	17.5	16–17	16–17	8
Triplet profile, SAF84/Sha31 ratio at 22– 24 kDa	Single	Single	Double	Single	Absent
Core stability: SAF84 and L42	Low	Low	Low	High	NA
PrP C-terminus ~ 154–234^d	Present	Present	Present	Present	Absent

Nine parameters of PrP^Sc obtained after differential PK digestion of TSE infected goat brain and WB. Epitope location determines the outcome. The italic texts indicate differences between CS-1 and CS-2. Between parentheses are the ranges in quantitative values as obtained in Triplex-WB (Sha31 related), ISS-WB (SAF84 related) or ELISA (SAF34 + Bar224 related). The ranges are relative to the different categories, not absolute, and should be compared per experiment with proper controls (BSE, CS-1, CS-2, CS-CH1641). ND: analysis not done, NA: not applicable due to absence of a classical PrP^res triplet. These typing tests may well work also on sheep TSE samples
^aGlycoprofile estimated by ISS-WB with SAF84 did show similar discriminatory properties as with Sha31 for C-1, CS-2, and CH1641 M/D values > 0.4 and BSE < 0.4, and N percentages for CS > 13% and BSE < 13%
^bResult with 12B2/Sha31 from Triplex-WB, P4/SAF84 from ISS-WB and SAF34 + Bar224 from CEA ELISA
^cThese two rows represent the same differentiating parameter. Differences between ISS-WB and Triplex-WB in molecular mass values are due to use of different gel systems and molecular mass standards
^dAbsence of PrP region ~ 154–234 is based on presence of Sha31 epitope and absence of SAF84 epitope corroborating interpretations by Pirisinu et al. [45]
^eThe molecular mass of the N-fraction of PrP^res#1 triplet is estimated to be 18.5 kDa, and that of the PrP^res#2 triplet 10 kDa (see Figure 2).

ISSN: 1297-9716