Just shift the values in z up by constant...
maxV=100;
minV=5;
f = 30;
fs = 1e4; % samples per second
t=0:0.1:1000;
x = sin(2*3.14*f*t);
M=[maxV-minV]/2; % slope --> [maxV-minV]/[1-(-1)]
B=1+minV; % intercept
z=M*(x+B); % scale % intercept
z = z + 510; % scale
plot(t(:,1:1000),z(:,1:1000))