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Identification of the PR Prealbumin Proteins in Horse Serum
Identifisering av Pr prealbumin proteiner i hesteserum
Acta Veterinaria Scandinavica volume 18, pages 458–470 (1977)
Abstract
The Pr protein, which is one of the major equine acidic prealbumins and which consists of a large number of phenotypes, has been studied with regard to its chemical identity.
Serum samples of known Pr phenotype which had been treated with varying amounts of bovine trypsin were subjected to starch gel electrophoresis at pH 4.8. When a certain amount of trypsin was used, the Pr protein was markedly affected, whereas the other acidic prealbumins retained their normal electrophoreitic pattern.
Extracts from three different regions of the acidic prealbumin field were tested by the casein precipitating inhibition test (CPI-test). Marked antitrypsin effect appeared against the extract from the Pr zone but not against the extracts from the two other acidic prealbumin zones.
When acidic starch gel electrophoresis was combined with the CPI-test, a broad inhibitory zone appeared in the area of the Pr proteins.
Pr protein was isolated by the use of agarose gel electrophoresis and sepharose column chromatography. The isolated protein which was tested for purity by gel electrophoresis had a molecular weight of about 60,000.
It is concluded that the equine Pr protein corresponds to αi-antitrypsin.
Sammendrag
Pr-proteinet er et av de fremtredende proteiner i gruppen sure prealbuminer i hesteserum og har et stort antall fenotyper. Proteinet er undersøkt med henblikk på dets kjemiske identitet.
Serumprøver av en kjent Pr-fenotype som var blitt behandlet med varierende mengder med bovint trypsin, ble kjørt på stivelsesgelelektroforese ved pH 4.8. Ved tilsetning av en bestemt mengde trypsin, ble det en tydelig påvirkning på Pr-proteinene, mens de øvrige sure prealbuminer beholdt sitt normale elektroforesemønster.
Ekstrakter fra tre forskjellige soner av feltet med de sure prealbuminer ble testet ved hjelp av casein precipitation inhibition test (CPI-test). En tydelig antitrypsinvirkning viste seg mot ekstraktet fra Pr-sonen, derimot var det ingen reaksjon mot ekstraktene fra de to øvrige prealbuminsoner.
Ved bruk av elektroforese på sur stivelsesgel kombinert med CPI-test fremkom en bred hemningssone i Pr-proteinenes område.
Pr-protein ble isolert ved hjelp av elektroforese på agarosegel og sepharose-kromatografi. Renheten av det isolerte protein som hadde en molekylvekt på omkring 60 000, ble testet ved hjelp av gelelektroforese.
Det konkluderes med at Pr-proteinet i hesteserum tilsvarer α1-anti-trypsin.
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Acknowledgement
The author wishes to thank Dr. med. M. Fagerhol, Ulleval Hospital, Oslo and Dr. med. vet. M. Brænd, the Department of Internal Medicine I, Veterinary College of Norway, Oslo, for valuable advice and guidance during these investigations.
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Ek, N. Identification of the PR Prealbumin Proteins in Horse Serum. Acta Vet Scand 18, 458–470 (1977). https://doi.org/10.1186/BF03548409
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DOI: https://doi.org/10.1186/BF03548409