Simply include the ID
property in your request which will return all the Subscriber Profile Attributes (along with any other properties you want to retrieve). Here's a sample SOAP request envelope:
<?xml version="1.0" encoding="UTF-8"?>
<s:Envelope xmlns:s="http://www.w3.org/2003/05/soap-envelope" xmlns:a="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:u="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
<s:Header>
<a:Action s:mustUnderstand="1">Retrieve</a:Action>
<a:MessageID>urn:uuid:7e0cca04-57bd-4481-864c-6ea8039d2ea0</a:MessageID>
<a:ReplyTo>
<a:Address>http://schemas.xmlsoap.org/ws/2004/08/addressing/role/anonymous</a:Address>
</a:ReplyTo>
<a:To s:mustUnderstand="1">{{soapEndPoint}}/Service.asmx</a:To>
<fueloauth xmlns="http://exacttarget.com">{{accessToken}}</fueloauth>
</s:Header>
<s:Body xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<RetrieveRequestMsg xmlns="http://exacttarget.com/wsdl/partnerAPI">
<RetrieveRequest>
<ObjectType>Subscriber</ObjectType>
<Properties>SubscriberKey</Properties>
<Properties>ID</Properties>
<Properties>EmailAddress</Properties>
<Properties>Status</Properties>
<Filter xmlns:q1="http://exacttarget.com/wsdl/partnerAPI" xsi:type="q1:SimpleFilterPart">
<q1:Property>SubscriberKey</q1:Property>
<q1:SimpleOperator>equals</q1:SimpleOperator>
<q1:Value>[email protected]</q1:Value>
</Filter>
</RetrieveRequest>
</RetrieveRequestMsg>
</s:Body>
</s:Envelope>