with that respect , 2 groups of proteins can be distinguished : ( 1 ) the group formed by the calcium-activated adenosine triphosphatase ( ca2 ( + ) -atpase ) of the sarcoplasmic reticulum , the beta 1-adrenergic and muscarinic receptors and the low affinity isoform of the na+k ( + ) -atpase .
C0033684
proteins
C0597298
isoform